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<h2 id="获取模型"><a href="#获取模型" class="headerlink" title="获取模型"></a>获取模型</h2><h3 id="get-函数"><a href="#get-函数" class="headerlink" title="get 函数"></a>get 函数</h3><figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div><div class="line">15</div><div class="line">16</div><div class="line">17</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">get</span><span class="params">($columns = [<span class="string">'*'</span>])</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> $builder = <span class="keyword">$this</span>->applyScopes();</div><div class="line"></div><div class="line"> <span class="keyword">if</span> (count($models = $builder->getModels($columns)) > <span class="number">0</span>) {</div><div class="line"> $models = $builder->eagerLoadRelations($models);</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">return</span> $builder->getModel()->newCollection($models);</div><div class="line">}</div><div class="line"></div><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">getModels</span><span class="params">($columns = [<span class="string">'*'</span>])</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->model->hydrate(</div><div class="line"> <span class="keyword">$this</span>->query->get($columns)->all()</div><div class="line"> )->all();</div><div class="line">}</div></pre></td></tr></table></figure>
<p><code>get</code> 函数会将 <code>QueryBuilder</code> 所获取的数据进一步包装 <code>hydrate</code>。<code>hydrate</code> 函数会将数据库取回来的数据打包成数据库模型对象 <code>Eloquent Model</code>，如果可以获取到数据，还会利用函数 <code>eagerLoadRelations</code> 来预加载关系模型。</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">hydrate</span><span class="params">(array $items)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> $instance = <span class="keyword">$this</span>->newModelInstance();</div><div class="line"></div><div class="line"> <span class="keyword">return</span> $instance->newCollection(array_map(<span class="function"><span class="keyword">function</span> <span class="params">($item)</span> <span class="title">use</span> <span class="params">($instance)</span> </span>{</div><div class="line"> <span class="keyword">return</span> $instance->newFromBuilder($item);</div><div class="line"> }, $items));</div><div class="line">}</div></pre></td></tr></table></figure>
<p><code>newModelInstance</code> 函数创建了一个新的数据库模型对象，重要的是这个函数为新的数据库模型对象赋予了 <code>connection</code>：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">newModelInstance</span><span class="params">($attributes = [])</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->model->newInstance($attributes)->setConnection(</div><div class="line"> <span class="keyword">$this</span>->query->getConnection()->getName()</div><div class="line"> );</div><div class="line">}</div></pre></td></tr></table></figure>
<p><code>newFromBuilder</code> 函数会将所有数据库数据存入另一个新的 <code>Eloquent Model</code> 的 <code>attributes</code> 中：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">newFromBuilder</span><span class="params">($attributes = [], $connection = null)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> $model = <span class="keyword">$this</span>->newInstance([], <span class="keyword">true</span>);</div><div class="line"></div><div class="line"> $model->setRawAttributes((<span class="keyword">array</span>) $attributes, <span class="keyword">true</span>);</div><div class="line"></div><div class="line"> $model->setConnection($connection ?: <span class="keyword">$this</span>->getConnectionName());</div><div class="line"></div><div class="line"> $model->fireModelEvent(<span class="string">'retrieved'</span>, <span class="keyword">false</span>);</div><div class="line"></div><div class="line"> <span class="keyword">return</span> $model;</div><div class="line">}</div></pre></td></tr></table></figure>
<p>newInstance 函数专用于创建新的数据库对象模型：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">newInstance</span><span class="params">($attributes = [], $exists = false)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> $model = <span class="keyword">new</span> <span class="keyword">static</span>((<span class="keyword">array</span>) $attributes);</div><div class="line"></div><div class="line"> $model->exists = $exists;</div><div class="line"></div><div class="line"> $model->setConnection(</div><div class="line"> <span class="keyword">$this</span>->getConnectionName()</div><div class="line"> );</div><div class="line"></div><div class="line"> <span class="keyword">return</span> $model;</div><div class="line">}</div></pre></td></tr></table></figure>
<p>值得注意的是 <code>newInstance</code> 将 <code>exist</code> 设置为 <code>true</code>，意味着当前这个数据库模型对象是从数据库中获取而来，并非是手动新建的，这个 <code>exist</code> 为真，我们才能对这个数据库对象进行 <code>update</code>。</p>
<p><code>setRawAttributes</code> 函数为新的数据库对象赋予属性值，并且进行 <code>sync</code>，标志着对象的原始状态：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div><div class="line">15</div><div class="line">16</div><div class="line">17</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">setRawAttributes</span><span class="params">(array $attributes, $sync = false)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">$this</span>->attributes = $attributes;</div><div class="line"></div><div class="line"> <span class="keyword">if</span> ($sync) {</div><div class="line"> <span class="keyword">$this</span>->syncOriginal();</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>;</div><div class="line">}</div><div class="line"></div><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">syncOriginal</span><span class="params">()</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">$this</span>->original = <span class="keyword">$this</span>->attributes;</div><div class="line"></div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>;</div><div class="line">}</div></pre></td></tr></table></figure>
<p>这个原始状态的记录十分重要，原因是 <code>save</code> 函数就是利用原始值 <code>original</code> 与属性值 <code>attributes</code> 的差异来决定更新的字段。</p>
<h3 id="find-函数"><a href="#find-函数" class="headerlink" title="find 函数"></a>find 函数</h3><p><code>find</code> 函数用于利用主键 <code>id</code> 来查询数据，<code>find</code> 函数也可以传入数组，查询多个数据</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div><div class="line">15</div><div class="line">16</div><div class="line">17</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">find</span><span class="params">($id, $columns = [<span class="string">'*'</span>])</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">if</span> (is_array($id) || $id <span class="keyword">instanceof</span> Arrayable) {</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->findMany($id, $columns);</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->whereKey($id)->first($columns);</div><div class="line">}</div><div class="line"></div><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">findMany</span><span class="params">($ids, $columns = [<span class="string">'*'</span>])</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">if</span> (<span class="keyword">empty</span>($ids)) {</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->model->newCollection();</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->whereKey($ids)->get($columns);</div><div class="line">}</div></pre></td></tr></table></figure>
<h3 id="findOrFail"><a href="#findOrFail" class="headerlink" title="findOrFail"></a>findOrFail</h3><p><code>laravel</code> 还提供 <code>findOrFail</code> 函数，一般用于 <code>controller</code>，在未找到记录的时候会抛出异常。</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div><div class="line">15</div><div class="line">16</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">findOrFail</span><span class="params">($id, $columns = [<span class="string">'*'</span>])</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> $result = <span class="keyword">$this</span>->find($id, $columns);</div><div class="line"></div><div class="line"> <span class="keyword">if</span> (is_array($id)) {</div><div class="line"> <span class="keyword">if</span> (count($result) == count(array_unique($id))) {</div><div class="line"> <span class="keyword">return</span> $result;</div><div class="line"> }</div><div class="line"> } <span class="keyword">elseif</span> (! is_null($result)) {</div><div class="line"> <span class="keyword">return</span> $result;</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">throw</span> (<span class="keyword">new</span> ModelNotFoundException)->setModel(</div><div class="line"> get_class(<span class="keyword">$this</span>->model), $id</div><div class="line"> );</div><div class="line">}</div></pre></td></tr></table></figure>
<h3 id="其他查询与数据获取方法"><a href="#其他查询与数据获取方法" class="headerlink" title="其他查询与数据获取方法"></a>其他查询与数据获取方法</h3><p>所用 <code>Query Builder</code> 支持的查询方法，例如 <code>select</code>、<code>selectSub</code>、<code>whereDate</code>、<code>whereBetween</code> 等等，都可以直接对 <code>Eloquent Model</code> 直接使用，程序会通过魔术方法调用 <code>Query Builder</code> 的相关方法：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div><div class="line">15</div><div class="line">16</div><div class="line">17</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">protected</span> $passthru = [</div><div class="line"> <span class="string">'insert'</span>, <span class="string">'insertGetId'</span>, <span class="string">'getBindings'</span>, <span class="string">'toSql'</span>,</div><div class="line"> <span class="string">'exists'</span>, <span class="string">'count'</span>, <span class="string">'min'</span>, <span class="string">'max'</span>, <span class="string">'avg'</span>, <span class="string">'sum'</span>, <span class="string">'getConnection'</span>,</div><div class="line">];</div><div class="line"></div><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">__call</span><span class="params">($method, $parameters)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> ...</div><div class="line"> </div><div class="line"> <span class="keyword">if</span> (in_array($method, <span class="keyword">$this</span>->passthru)) {</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->toBase()->{$method}(...$parameters);</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">$this</span>->query->{$method}(...$parameters);</div><div class="line"></div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>;</div><div class="line">}</div></pre></td></tr></table></figure>
<p><code>passthru</code> 中的各个函数在调用前需要加载查询作用域，原因是这些操作基本上是 <code>aggregate</code> 的，需要添加搜索条件才能更加符合预期：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">toBase</span><span class="params">()</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->applyScopes()->getQuery();</div><div class="line">}</div></pre></td></tr></table></figure>
<h2 id="添加和更新模型"><a href="#添加和更新模型" class="headerlink" title="添加和更新模型"></a>添加和更新模型</h2><h3 id="save-函数"><a href="#save-函数" class="headerlink" title="save 函数"></a>save 函数</h3><p>在 <code>Eloquent Model</code> 中，添加与更新模型可以统一用 <code>save</code> 函数。在添加模型的时候需要事先为 <code>model</code> 属性赋值，可以单个手动赋值，也可以批量赋值。在更新模型的时候，需要事先从数据库中取出模型，然后修改模型属性，最后执行 <code>save</code> 更新操作。官方文档：<a href="https://d.laravel-china.org/docs/5.5/eloquent#inserting-and-updating-models" target="_blank" rel="external">添加和更新模型</a> </p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div><div class="line">15</div><div class="line">16</div><div class="line">17</div><div class="line">18</div><div class="line">19</div><div class="line">20</div><div class="line">21</div><div class="line">22</div><div class="line">23</div><div class="line">24</div><div class="line">25</div><div class="line">26</div><div class="line">27</div><div class="line">28</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">save</span><span class="params">(array $options = [])</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> $query = <span class="keyword">$this</span>->newQueryWithoutScopes();</div><div class="line"></div><div class="line"> <span class="keyword">if</span> (<span class="keyword">$this</span>->fireModelEvent(<span class="string">'saving'</span>) === <span class="keyword">false</span>) {</div><div class="line"> <span class="keyword">return</span> <span class="keyword">false</span>;</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">if</span> (<span class="keyword">$this</span>->exists) {</div><div class="line"> $saved = <span class="keyword">$this</span>->isDirty() ?</div><div class="line"> <span class="keyword">$this</span>->performUpdate($query) : <span class="keyword">true</span>;</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">else</span> {</div><div class="line"> $saved = <span class="keyword">$this</span>->performInsert($query);</div><div class="line"></div><div class="line"> <span class="keyword">if</span> (! <span class="keyword">$this</span>->getConnectionName() &&</div><div class="line"> $connection = $query->getConnection()) {</div><div class="line"> <span class="keyword">$this</span>->setConnection($connection->getName());</div><div class="line"> }</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">if</span> ($saved) {</div><div class="line"> <span class="keyword">$this</span>->finishSave($options);</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">return</span> $saved;</div><div class="line">}</div></pre></td></tr></table></figure>
<p><code>save</code> 函数不会加载全局作用域，原因是凡是利用 <code>save</code> 函数进行的插入或者更新的操作都不会存在 <code>where</code> 条件，仅仅利用自身的主键属性来进行更新。如果需要 <code>where</code> 条件可以使用 <code>query\builder</code> 的 <code>update</code> 函数，我们在下面会详细介绍：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div><div class="line">15</div><div class="line">16</div><div class="line">17</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">newQueryWithoutScopes</span><span class="params">()</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> $builder = <span class="keyword">$this</span>->newEloquentBuilder(<span class="keyword">$this</span>->newBaseQueryBuilder());</div><div class="line"></div><div class="line"> <span class="keyword">return</span> $builder->setModel(<span class="keyword">$this</span>)</div><div class="line"> ->with(<span class="keyword">$this</span>->with)</div><div class="line"> ->withCount(<span class="keyword">$this</span>->withCount);</div><div class="line">}</div><div class="line"></div><div class="line"><span class="keyword">protected</span> <span class="function"><span class="keyword">function</span> <span class="title">newBaseQueryBuilder</span><span class="params">()</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> $connection = <span class="keyword">$this</span>->getConnection();</div><div class="line"></div><div class="line"> <span class="keyword">return</span> <span class="keyword">new</span> QueryBuilder(</div><div class="line"> $connection, $connection->getQueryGrammar(), $connection->getPostProcessor()</div><div class="line"> );</div><div class="line">}</div></pre></td></tr></table></figure>
<p>newQueryWithoutScopes 函数创建新的没有任何其他条件的 <code>Eloquent\builder</code> 类，而 <code>Eloquent\builder</code> 类需要 <code>Query\builder</code> 类作为底层查询构造器。</p>
<h3 id="performUpdate-函数"><a href="#performUpdate-函数" class="headerlink" title="performUpdate 函数"></a>performUpdate 函数</h3><p>如果当前的数据库模型对象是从数据库中取出的，也就是直接或间接的调用 <code>get()</code> 函数从数据库中获取到的数据库对象，那么其 <code>exists</code> 必然是 <code>true</code></p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div><div class="line">15</div><div class="line">16</div><div class="line">17</div><div class="line">18</div><div class="line">19</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">isDirty</span><span class="params">($attributes = null)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->hasChanges(</div><div class="line"> <span class="keyword">$this</span>->getDirty(), is_array($attributes) ? $attributes : func_get_args()</div><div class="line"> );</div><div class="line">}</div><div class="line"></div><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">getDirty</span><span class="params">()</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> $dirty = [];</div><div class="line"></div><div class="line"> <span class="keyword">foreach</span> (<span class="keyword">$this</span>->getAttributes() <span class="keyword">as</span> $key => $value) {</div><div class="line"> <span class="keyword">if</span> (! <span class="keyword">$this</span>->originalIsEquivalent($key, $value)) {</div><div class="line"> $dirty[$key] = $value;</div><div class="line"> }</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">return</span> $dirty;</div><div class="line">}</div></pre></td></tr></table></figure>
<p><code>getDirty</code> 函数可以获取所有与原始值不同的属性值，也就是需要更新的数据库字段。关键函数在于 <code>originalIsEquivalent</code>：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div><div class="line">15</div><div class="line">16</div><div class="line">17</div><div class="line">18</div><div class="line">19</div><div class="line">20</div><div class="line">21</div><div class="line">22</div><div class="line">23</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">protected</span> <span class="function"><span class="keyword">function</span> <span class="title">originalIsEquivalent</span><span class="params">($key, $current)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">if</span> (! array_key_exists($key, <span class="keyword">$this</span>->original)) {</div><div class="line"> <span class="keyword">return</span> <span class="keyword">false</span>;</div><div class="line"> }</div><div class="line"></div><div class="line"> $original = <span class="keyword">$this</span>->getOriginal($key);</div><div class="line"></div><div class="line"> <span class="keyword">if</span> ($current === $original) {</div><div class="line"> <span class="keyword">return</span> <span class="keyword">true</span>;</div><div class="line"> } <span class="keyword">elseif</span> (is_null($current)) {</div><div class="line"> <span class="keyword">return</span> <span class="keyword">false</span>;</div><div class="line"> } <span class="keyword">elseif</span> (<span class="keyword">$this</span>->isDateAttribute($key)) {</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->fromDateTime($current) ===</div><div class="line"> <span class="keyword">$this</span>->fromDateTime($original);</div><div class="line"> } <span class="keyword">elseif</span> (<span class="keyword">$this</span>->hasCast($key)) {</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->castAttribute($key, $current) ===</div><div class="line"> <span class="keyword">$this</span>->castAttribute($key, $original);</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">return</span> is_numeric($current) && is_numeric($original)</div><div class="line"> && strcmp((string) $current, (string) $original) === <span class="number">0</span>;</div><div class="line">}</div></pre></td></tr></table></figure>
<p>可以看到，对于数据库可以转化的属性都要先进行转化，然后再开始对比。比较出的结果，就是我们需要 <code>update</code> 的字段。</p>
<p>执行更新的时候，除了 <code>getDirty</code> 函数获得的待更新字段，还会有 <code>UPDATED_AT</code> 这个字段：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div><div class="line">15</div><div class="line">16</div><div class="line">17</div><div class="line">18</div><div class="line">19</div><div class="line">20</div><div class="line">21</div><div class="line">22</div><div class="line">23</div><div class="line">24</div><div class="line">25</div><div class="line">26</div><div class="line">27</div><div class="line">28</div><div class="line">29</div><div class="line">30</div><div class="line">31</div><div class="line">32</div><div class="line">33</div><div class="line">34</div><div class="line">35</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">protected</span> <span class="function"><span class="keyword">function</span> <span class="title">performUpdate</span><span class="params">(Builder $query)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">if</span> (<span class="keyword">$this</span>->fireModelEvent(<span class="string">'updating'</span>) === <span class="keyword">false</span>) {</div><div class="line"> <span class="keyword">return</span> <span class="keyword">false</span>;</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">if</span> (<span class="keyword">$this</span>->usesTimestamps()) {</div><div class="line"> <span class="keyword">$this</span>->updateTimestamps();</div><div class="line"> }</div><div class="line"></div><div class="line"> $dirty = <span class="keyword">$this</span>->getDirty();</div><div class="line"></div><div class="line"> <span class="keyword">if</span> (count($dirty) > <span class="number">0</span>) {</div><div class="line"> <span class="keyword">$this</span>->setKeysForSaveQuery($query)->update($dirty);</div><div class="line"></div><div class="line"> <span class="keyword">$this</span>->fireModelEvent(<span class="string">'updated'</span>, <span class="keyword">false</span>);</div><div class="line"></div><div class="line"> <span class="keyword">$this</span>->syncChanges();</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">return</span> <span class="keyword">true</span>;</div><div class="line">}</div><div class="line"></div><div class="line"><span class="keyword">protected</span> <span class="function"><span class="keyword">function</span> <span class="title">updateTimestamps</span><span class="params">()</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> $time = <span class="keyword">$this</span>->freshTimestamp();</div><div class="line"></div><div class="line"> <span class="keyword">if</span> (! is_null(<span class="keyword">static</span>::UPDATED_AT) && ! <span class="keyword">$this</span>->isDirty(<span class="keyword">static</span>::UPDATED_AT)) {</div><div class="line"> <span class="keyword">$this</span>->setUpdatedAt($time);</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">if</span> (! <span class="keyword">$this</span>->exists && ! <span class="keyword">$this</span>->isDirty(<span class="keyword">static</span>::CREATED_AT)) {</div><div class="line"> <span class="keyword">$this</span>->setCreatedAt($time);</div><div class="line"> }</div><div class="line">}</div></pre></td></tr></table></figure>
<p>执行更新的时候，<code>where</code> 条件只有一个，那就是主键 <code>id</code>：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div><div class="line">15</div><div class="line">16</div><div class="line">17</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">protected</span> <span class="function"><span class="keyword">function</span> <span class="title">setKeysForSaveQuery</span><span class="params">(Builder $query)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> $query->where(<span class="keyword">$this</span>->getKeyName(), <span class="string">'='</span>, <span class="keyword">$this</span>->getKeyForSaveQuery());</div><div class="line"></div><div class="line"> <span class="keyword">return</span> $query;</div><div class="line">}</div><div class="line"></div><div class="line"><span class="keyword">protected</span> <span class="function"><span class="keyword">function</span> <span class="title">getKeyForSaveQuery</span><span class="params">()</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->original[<span class="keyword">$this</span>->getKeyName()]</div><div class="line"> ?? <span class="keyword">$this</span>->getKey();</div><div class="line">}</div><div class="line"></div><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">getKey</span><span class="params">()</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->getAttribute(<span class="keyword">$this</span>->getKeyName());</div><div class="line">}</div></pre></td></tr></table></figure>
<p>最后会调用 <code>EloquentBuilder</code> 的 <code>update</code> 函数：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div><div class="line">15</div><div class="line">16</div><div class="line">17</div><div class="line">18</div><div class="line">19</div><div class="line">20</div><div class="line">21</div><div class="line">22</div><div class="line">23</div><div class="line">24</div><div class="line">25</div><div class="line">26</div><div class="line">27</div><div class="line">28</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">update</span><span class="params">(array $values)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->toBase()->update(<span class="keyword">$this</span>->addUpdatedAtColumn($values));</div><div class="line">}</div><div class="line"></div><div class="line"><span class="keyword">protected</span> <span class="function"><span class="keyword">function</span> <span class="title">addUpdatedAtColumn</span><span class="params">(array $values)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">if</span> (! <span class="keyword">$this</span>->model->usesTimestamps()) {</div><div class="line"> <span class="keyword">return</span> $values;</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">return</span> Arr::add(</div><div class="line"> $values, <span class="keyword">$this</span>->model->getUpdatedAtColumn(),</div><div class="line"> <span class="keyword">$this</span>->model->freshTimestampString()</div><div class="line"> );</div><div class="line">}</div><div class="line"></div><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">freshTimestampString</span><span class="params">()</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->fromDateTime(<span class="keyword">$this</span>->freshTimestamp());</div><div class="line">}</div><div class="line"></div><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">fromDateTime</span><span class="params">($value)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">return</span> is_null($value) ? $value : <span class="keyword">$this</span>->asDateTime($value)->format(</div><div class="line"> <span class="keyword">$this</span>->getDateFormat()</div><div class="line"> );</div><div class="line">}</div></pre></td></tr></table></figure>
<h3 id="performInsert"><a href="#performInsert" class="headerlink" title="performInsert"></a>performInsert</h3><p>关于数据库对象的插入，如果数据库的主键被设置为 <code>increment</code>，也就是自增的话，程序会调用 <code>insertAndSetId</code>，这个时候不需要给数据库模型对象手动赋值主键 <code>id</code>。若果数据库的主键并不支持自增，那么就需要在插入前，为数据库对象的主键 <code>id</code> 赋值，否则数据库会报错。</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div><div class="line">15</div><div class="line">16</div><div class="line">17</div><div class="line">18</div><div class="line">19</div><div class="line">20</div><div class="line">21</div><div class="line">22</div><div class="line">23</div><div class="line">24</div><div class="line">25</div><div class="line">26</div><div class="line">27</div><div class="line">28</div><div class="line">29</div><div class="line">30</div><div class="line">31</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">protected</span> <span class="function"><span class="keyword">function</span> <span class="title">performInsert</span><span class="params">(Builder $query)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">if</span> (<span class="keyword">$this</span>->fireModelEvent(<span class="string">'creating'</span>) === <span class="keyword">false</span>) {</div><div class="line"> <span class="keyword">return</span> <span class="keyword">false</span>;</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">if</span> (<span class="keyword">$this</span>->usesTimestamps()) {</div><div class="line"> <span class="keyword">$this</span>->updateTimestamps();</div><div class="line"> }</div><div class="line"></div><div class="line"> $attributes = <span class="keyword">$this</span>->attributes;</div><div class="line"></div><div class="line"> <span class="keyword">if</span> (<span class="keyword">$this</span>->getIncrementing()) {</div><div class="line"> <span class="keyword">$this</span>->insertAndSetId($query, $attributes);</div><div class="line"> }</div><div class="line"> <span class="keyword">else</span> {</div><div class="line"> <span class="keyword">if</span> (<span class="keyword">empty</span>($attributes)) {</div><div class="line"> <span class="keyword">return</span> <span class="keyword">true</span>;</div><div class="line"> }</div><div class="line"></div><div class="line"> $query->insert($attributes);</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">$this</span>->exists = <span class="keyword">true</span>;</div><div class="line"></div><div class="line"> <span class="keyword">$this</span>->wasRecentlyCreated = <span class="keyword">true</span>;</div><div class="line"></div><div class="line"> <span class="keyword">$this</span>->fireModelEvent(<span class="string">'created'</span>, <span class="keyword">false</span>);</div><div class="line"></div><div class="line"> <span class="keyword">return</span> <span class="keyword">true</span>;</div><div class="line">}</div></pre></td></tr></table></figure>
<p><code>laravel</code> 默认数据库的主键支持自增属性，程序调用的也是函数 <code>insertAndSetId</code> 函数：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">protected</span> <span class="function"><span class="keyword">function</span> <span class="title">insertAndSetId</span><span class="params">(Builder $query, $attributes)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> $id = $query->insertGetId($attributes, $keyName = <span class="keyword">$this</span>->getKeyName());</div><div class="line"></div><div class="line"> <span class="keyword">$this</span>->setAttribute($keyName, $id);</div><div class="line">}</div></pre></td></tr></table></figure>
<p>插入后，会将插入后得到的主键 <code>id</code> 返回，并赋值到模型的属性当中。</p>
<p>如果数据库主键不支持自增，那么我们在数据库类中要设置：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> $incrementing = <span class="keyword">false</span>;</div></pre></td></tr></table></figure>
<p>每次进行插入数据的时候，需要手动给主键赋值。</p>
<h3 id="update-函数"><a href="#update-函数" class="headerlink" title="update 函数"></a>update 函数</h3><p><code>save</code> 函数仅仅支持手动的属性赋值，无法批量赋值。<code>laravel</code> 的 <code>Eloquent Model</code> 还有一个函数: <code>update</code> 支持批量属性赋值。有意思的是，<code>Eloquent Builder</code> 也有函数 <code>update</code>，那个是上一小节提到的 <code>performUpdate</code> 所调用的函数。</p>
<p>两个 <code>update</code> 功能一致，只是 <code>Model</code> 的 <code>update</code> 函数比较适用于更新从数据库取回的数据库对象：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div></pre></td><td class="code"><pre><div class="line">$flight = App\Flight::find(<span class="number">1</span>);</div><div class="line"></div><div class="line">$flight->update([<span class="string">'name'</span> => <span class="string">'New Flight Name'</span>,<span class="string">'desc'</span> => <span class="string">'test'</span>]);</div></pre></td></tr></table></figure>
<p>而 <code>Builder</code> 的 <code>update</code> 适用于多查询条件下的更新：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div></pre></td><td class="code"><pre><div class="line">App\Flight::where(<span class="string">'active'</span>, <span class="number">1</span>)</div><div class="line"> ->where(<span class="string">'destination'</span>, <span class="string">'San Diego'</span>)</div><div class="line"> ->update([<span class="string">'delayed'</span> => <span class="number">1</span>]);</div></pre></td></tr></table></figure>
<p>无论哪一种，都会自动更新 <code>updated_at</code> 字段。</p>
<p><code>Model</code> 的 <code>update</code> 函数借助 <code>fill</code> 函数与 <code>save</code> 函数：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">update</span><span class="params">(array $attributes = [], array $options = [])</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">if</span> (! <span class="keyword">$this</span>->exists) {</div><div class="line"> <span class="keyword">return</span> <span class="keyword">false</span>;</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->fill($attributes)->save($options);</div><div class="line">}</div></pre></td></tr></table></figure>
<h3 id="make-函数"><a href="#make-函数" class="headerlink" title="make 函数"></a>make 函数</h3><p>同样的，<code>save</code> 的插入也仅仅支持手动属性赋值，如果想实现批量属性赋值的插入可以使用 <code>make</code> 函数：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div></pre></td><td class="code"><pre><div class="line">$model = App\Flight::make([<span class="string">'name'</span> => <span class="string">'New Flight Name'</span>,<span class="string">'desc'</span> => <span class="string">'test'</span>]);</div><div class="line"></div><div class="line">$model->save();</div></pre></td></tr></table></figure>
<p><code>make</code> 函数实际上仅仅是新建了一个 <code>Eloquent Model</code>，并批量赋予属性值：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">make</span><span class="params">(array $attributes = [])</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->newModelInstance($attributes);</div><div class="line">}</div><div class="line"></div><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">newModelInstance</span><span class="params">($attributes = [])</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->model->newInstance($attributes)->setConnection(</div><div class="line"> <span class="keyword">$this</span>->query->getConnection()->getName()</div><div class="line"> );</div><div class="line">}</div></pre></td></tr></table></figure>
<h3 id="create-函数"><a href="#create-函数" class="headerlink" title="create 函数"></a>create 函数</h3><p>如果想要一步到位，批量赋值属性与插入一起操作，可以使用 <code>create</code> 函数：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div></pre></td><td class="code"><pre><div class="line">App\Flight::create([<span class="string">'name'</span> => <span class="string">'New Flight Name'</span>,<span class="string">'desc'</span> => <span class="string">'test'</span>]);</div></pre></td></tr></table></figure>
<p>相比较 <code>make</code> 函数，<code>create</code> 函数更进一步调用了 <code>save</code> 函数：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">create</span><span class="params">(array $attributes = [])</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">return</span> tap(<span class="keyword">$this</span>->newModelInstance($attributes), <span class="function"><span class="keyword">function</span> <span class="params">($instance)</span> </span>{</div><div class="line"> $instance->save();</div><div class="line"> });</div><div class="line">}</div></pre></td></tr></table></figure>
<p>实际上，属性值是否可以批量赋值需要受 <code>fillable</code> 或 <code>guarded</code> 来控制，如果我们想要强制批量赋值可以使用 <code>forceCreate</code>：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">forceCreate</span><span class="params">(array $attributes)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->model->unguarded(<span class="function"><span class="keyword">function</span> <span class="params">()</span> <span class="title">use</span> <span class="params">($attributes)</span> </span>{</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->newModelInstance()->create($attributes);</div><div class="line"> });</div><div class="line">}</div></pre></td></tr></table></figure>
<h3 id="findOrNew-函数"><a href="#findOrNew-函数" class="headerlink" title="findOrNew 函数"></a>findOrNew 函数</h3><p><code>laravel</code> 提供一种主键查询或者新建数据库对象的函数：<code>findOrNew</code>：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">findOrNew</span><span class="params">($id, $columns = [<span class="string">'*'</span>])</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">if</span> (! is_null($model = <span class="keyword">$this</span>->find($id, $columns))) {</div><div class="line"> <span class="keyword">return</span> $model;</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->newModelInstance();</div><div class="line">}</div></pre></td></tr></table></figure>
<p>值得注意的是，当查询失败的时候，会返回一个全新的数据库对象，不含有任何 <code>attributes</code>。</p>
<h3 id="firstOrNew-函数"><a href="#firstOrNew-函数" class="headerlink" title="firstOrNew 函数"></a>firstOrNew 函数</h3><p><code>laravel</code> 提供一种自定义查询或者新建数据库对象的函数：<code>firstOrNew</code>：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">firstOrNew</span><span class="params">(array $attributes, array $values = [])</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">if</span> (! is_null($instance = <span class="keyword">$this</span>->where($attributes)->first())) {</div><div class="line"> <span class="keyword">return</span> $instance;</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->newModelInstance($attributes + $values);</div><div class="line">}</div></pre></td></tr></table></figure>
<p>值得注意的是，如果查询失败，会返回一个含有 <code>attributes</code> 和 <code>values</code> 两者合并的属性的数据库对象。</p>
<h3 id="firstOrCreate-函数"><a href="#firstOrCreate-函数" class="headerlink" title="firstOrCreate 函数"></a>firstOrCreate 函数</h3><p>类似于 <code>firstOrNew</code> 函数，<code>firstOrCreate</code> 函数也用于自定义查询或者新建数据库对象，不同的是，<code>firstOrCreate</code> 函数还进一步对数据进行了插入操作：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">firstOrCreate</span><span class="params">(array $attributes, array $values = [])</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">if</span> (! is_null($instance = <span class="keyword">$this</span>->where($attributes)->first())) {</div><div class="line"> <span class="keyword">return</span> $instance;</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">return</span> tap(<span class="keyword">$this</span>->newModelInstance($attributes + $values), <span class="function"><span class="keyword">function</span> <span class="params">($instance)</span> </span>{</div><div class="line"> $instance->save();</div><div class="line"> });</div><div class="line">}</div></pre></td></tr></table></figure>
<h3 id="updateOrCreate-函数"><a href="#updateOrCreate-函数" class="headerlink" title="updateOrCreate 函数"></a>updateOrCreate 函数</h3><p>在 <code>firstOrCreate</code> 函数基础上，除了对数据进行查询，还会对查询成功的数据利用 <code>value</code> 进行更新：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">updateOrCreate</span><span class="params">(array $attributes, array $values = [])</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">return</span> tap(<span class="keyword">$this</span>->firstOrNew($attributes), <span class="function"><span class="keyword">function</span> <span class="params">($instance)</span> <span class="title">use</span> <span class="params">($values)</span> </span>{</div><div class="line"> $instance->fill($values)->save();</div><div class="line"> });</div><div class="line">}</div></pre></td></tr></table></figure>
<h3 id="firstOr-函数"><a href="#firstOr-函数" class="headerlink" title="firstOr 函数"></a>firstOr 函数</h3><p>如果想要自定义查找失败后的操作，可以使用 <code>firstOr</code> 函数，该函数可以传入闭包函数，处理找不到数据的情况：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">firstOr</span><span class="params">($columns = [<span class="string">'*'</span>], Closure $callback = null)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">if</span> ($columns <span class="keyword">instanceof</span> Closure) {</div><div class="line"> $callback = $columns;</div><div class="line"></div><div class="line"> $columns = [<span class="string">'*'</span>];</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">if</span> (! is_null($model = <span class="keyword">$this</span>->first($columns))) {</div><div class="line"> <span class="keyword">return</span> $model;</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">return</span> call_user_func($callback);</div><div class="line">}</div></pre></td></tr></table></figure>
<h2 id="删除模型"><a href="#删除模型" class="headerlink" title="删除模型"></a>删除模型</h2><p>删除模型也会分为两种，一种是针对 <code>Eloquent Model</code> 的删除，这种删除必须是从数据库中取出的对象。还有一种是 <code>Eloquent Builder</code> 的删除，这种删除一般会带有多个查询条件。我们这一小节主要讲 <code>model</code> 的删除：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div><div class="line">15</div><div class="line">16</div><div class="line">17</div><div class="line">18</div><div class="line">19</div><div class="line">20</div><div class="line">21</div><div class="line">22</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">delete</span><span class="params">()</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">if</span> (is_null(<span class="keyword">$this</span>->getKeyName())) {</div><div class="line"> <span class="keyword">throw</span> <span class="keyword">new</span> <span class="keyword">Exception</span>(<span class="string">'No primary key defined on model.'</span>);</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">if</span> (! <span class="keyword">$this</span>->exists) {</div><div class="line"> <span class="keyword">return</span>;</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">if</span> (<span class="keyword">$this</span>->fireModelEvent(<span class="string">'deleting'</span>) === <span class="keyword">false</span>) {</div><div class="line"> <span class="keyword">return</span> <span class="keyword">false</span>;</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">$this</span>->touchOwners();</div><div class="line"></div><div class="line"> <span class="keyword">$this</span>->performDeleteOnModel();</div><div class="line"></div><div class="line"> <span class="keyword">$this</span>->fireModelEvent(<span class="string">'deleted'</span>, <span class="keyword">false</span>);</div><div class="line"></div><div class="line"> <span class="keyword">return</span> <span class="keyword">true</span>;</div><div class="line">}</div></pre></td></tr></table></figure>
<p>删除模型时，模型对象必然要有主键。<code>performDeleteOnModel</code> 函数执行具体的删除操作：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">protected</span> <span class="function"><span class="keyword">function</span> <span class="title">performDeleteOnModel</span><span class="params">()</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">$this</span>->setKeysForSaveQuery(<span class="keyword">$this</span>->newQueryWithoutScopes())->delete();</div><div class="line"></div><div class="line"> <span class="keyword">$this</span>->exists = <span class="keyword">false</span>;</div><div class="line">}</div><div class="line"></div><div class="line"><span class="keyword">protected</span> <span class="function"><span class="keyword">function</span> <span class="title">setKeysForSaveQuery</span><span class="params">(Builder $query)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> $query->where(<span class="keyword">$this</span>->getKeyName(), <span class="string">'='</span>, <span class="keyword">$this</span>->getKeyForSaveQuery());</div><div class="line"></div><div class="line"> <span class="keyword">return</span> $query;</div><div class="line">}</div></pre></td></tr></table></figure>
<p>所以实际上，<code>Model</code> 调用的也是 <code>builder</code> 的 <code>delete</code> 函数。</p>
<h3 id="软删除"><a href="#软删除" class="headerlink" title="软删除"></a>软删除</h3><p>如果想要使用软删除，需要使用 <code>Illuminate\Database\Eloquent\SoftDeletes</code> 这个 trait。并且需要定义软删除字段，默认为 <code>deleted_at</code>，将软删除字段放入 <code>dates</code> 中，具体用法可参考官方文档:<a href="https://d.laravel-china.org/docs/5.5/eloquent#soft-deleting" target="_blank" rel="external">软删除</a></p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div></pre></td><td class="code"><pre><div class="line"><span class="class"><span class="keyword">class</span> <span class="title">Flight</span> <span class="keyword">extends</span> <span class="title">Model</span></span></div><div class="line"><span class="class"></span>{</div><div class="line"> <span class="keyword">use</span> <span class="title">SoftDeletes</span>;</div><div class="line"></div><div class="line"> <span class="comment">/**</span></div><div class="line"><span class="comment"> * 需要被转换成日期的属性。</span></div><div class="line"><span class="comment"> *</span></div><div class="line"><span class="comment"> * <span class="doctag">@var</span> array</span></div><div class="line"><span class="comment"> */</span></div><div class="line"> <span class="keyword">protected</span> $dates = [<span class="string">'deleted_at'</span>];</div><div class="line">}</div></pre></td></tr></table></figure>
<p>我们先看看这个 <code>trait</code>：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">trait</span> SoftDeletes </div><div class="line">{</div><div class="line"> <span class="keyword">public</span> <span class="keyword">static</span> <span class="function"><span class="keyword">function</span> <span class="title">bootSoftDeletes</span><span class="params">()</span></span></div><div class="line"><span class="function"> </span>{</div><div class="line"> <span class="keyword">static</span>::addGlobalScope(<span class="keyword">new</span> SoftDeletingScope);</div><div class="line"> }</div><div class="line"></div><div class="line">}</div></pre></td></tr></table></figure>
<p>如果使用了软删除，在 <code>model</code> 的启动过程中，就会启动软删除的这个函数。可以看出来，软删除是需要查询作用域来合作发挥作用的。我们看看这个 <code>SoftDeletingScope</code> :</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div><div class="line">15</div><div class="line">16</div><div class="line">17</div><div class="line">18</div><div class="line">19</div><div class="line">20</div><div class="line">21</div><div class="line">22</div><div class="line">23</div><div class="line">24</div></pre></td><td class="code"><pre><div class="line"><span class="class"><span class="keyword">class</span> <span class="title">SoftDeletingScope</span> <span class="keyword">implements</span> <span class="title">Scope</span></span></div><div class="line"><span class="class"></span>{</div><div class="line"> <span class="keyword">protected</span> $extensions = [<span class="string">'Restore'</span>, <span class="string">'WithTrashed'</span>, <span class="string">'WithoutTrashed'</span>, <span class="string">'OnlyTrashed'</span>];</div><div class="line"> </div><div class="line"> <span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">apply</span><span class="params">(Builder $builder, Model $model)</span></span></div><div class="line"><span class="function"> </span>{</div><div class="line"> $builder->whereNull($model->getQualifiedDeletedAtColumn());</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">extend</span><span class="params">(Builder $builder)</span></span></div><div class="line"><span class="function"> </span>{</div><div class="line"> <span class="keyword">foreach</span> (<span class="keyword">$this</span>->extensions <span class="keyword">as</span> $extension) {</div><div class="line"> <span class="keyword">$this</span>->{<span class="string">"add{$extension}"</span>}($builder);</div><div class="line"> }</div><div class="line"></div><div class="line"> $builder->onDelete(<span class="function"><span class="keyword">function</span> <span class="params">(Builder $builder)</span> </span>{</div><div class="line"> $column = <span class="keyword">$this</span>->getDeletedAtColumn($builder);</div><div class="line"></div><div class="line"> <span class="keyword">return</span> $builder->update([</div><div class="line"> $column => $builder->getModel()->freshTimestampString(),</div><div class="line"> ]);</div><div class="line"> });</div><div class="line"> }</div><div class="line">}</div></pre></td></tr></table></figure>
<p><code>apply</code> 函数是加载全局域调用的函数，每次进行查询的时候，调用 <code>get</code> 函数就会自动加载这个函数，<code>whereNull</code> 这个查询条件会被加载到具体的 <code>where</code> 条件中。<code>deleted_at</code> 字段一般被设置为 <code>null</code>，在执行软删除的时候，该字段会被赋予时间格式的值，标志着被删除的时间。</p>
<p>在加载全局作用域的时候，还会调用 <code>extend</code> 函数，<code>extend</code> 函数为 <code>model</code> 添加了四个函数：</p>
<ul>
<li>WithTrashed</li>
</ul>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div></pre></td><td class="code"><pre><div class="line"> <span class="keyword">protected</span> <span class="function"><span class="keyword">function</span> <span class="title">addWithTrashed</span><span class="params">(Builder $builder)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> $builder->macro(<span class="string">'withTrashed'</span>, <span class="function"><span class="keyword">function</span> <span class="params">(Builder $builder)</span> </span>{</div><div class="line"> <span class="keyword">return</span> $builder->withoutGlobalScope(<span class="keyword">$this</span>);</div><div class="line"> });</div><div class="line">}</div></pre></td></tr></table></figure>
<p><code>withTrashed</code> 函数取消了软删除的全局作用域，这样我们查询数据的时候就会查询到正常数据和被软删除的数据。</p>
<ul>
<li>withoutTrashed</li>
</ul>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">protected</span> <span class="function"><span class="keyword">function</span> <span class="title">addWithoutTrashed</span><span class="params">(Builder $builder)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> $builder->macro(<span class="string">'withoutTrashed'</span>, <span class="function"><span class="keyword">function</span> <span class="params">(Builder $builder)</span> </span>{</div><div class="line"> $model = $builder->getModel();</div><div class="line"></div><div class="line"> $builder->withoutGlobalScope(<span class="keyword">$this</span>)->whereNull(</div><div class="line"> $model->getQualifiedDeletedAtColumn()</div><div class="line"> );</div><div class="line"></div><div class="line"> <span class="keyword">return</span> $builder;</div><div class="line"> });</div><div class="line">}</div></pre></td></tr></table></figure>
<p><code>withTrashed</code> 函数着重强调了不要获取软删除的数据。</p>
<ul>
<li>onlyTrashed</li>
</ul>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">protected</span> <span class="function"><span class="keyword">function</span> <span class="title">addOnlyTrashed</span><span class="params">(Builder $builder)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> $builder->macro(<span class="string">'onlyTrashed'</span>, <span class="function"><span class="keyword">function</span> <span class="params">(Builder $builder)</span> </span>{</div><div class="line"> $model = $builder->getModel();</div><div class="line"></div><div class="line"> $builder->withoutGlobalScope(<span class="keyword">$this</span>)->whereNotNull(</div><div class="line"> $model->getQualifiedDeletedAtColumn()</div><div class="line"> );</div><div class="line"></div><div class="line"> <span class="keyword">return</span> $builder;</div><div class="line"> });</div><div class="line">}</div></pre></td></tr></table></figure>
<p>如果只想获取被软删除的数据，可以使用这个函数 <code>onlyTrashed</code>，可以看到，它使用了 <code>whereNotNull</code>。</p>
<ul>
<li>restore</li>
</ul>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">protected</span> <span class="function"><span class="keyword">function</span> <span class="title">addRestore</span><span class="params">(Builder $builder)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> $builder->macro(<span class="string">'restore'</span>, <span class="function"><span class="keyword">function</span> <span class="params">(Builder $builder)</span> </span>{</div><div class="line"> $builder->withTrashed();</div><div class="line"></div><div class="line"> <span class="keyword">return</span> $builder->update([$builder->getModel()->getDeletedAtColumn() => <span class="keyword">null</span>]);</div><div class="line"> });</div><div class="line">}</div></pre></td></tr></table></figure>
<p>如果想要恢复被删除的数据，还可以使用 <code>restore</code>，重新将 <code>deleted_at</code> 数据恢复为 null。</p>
<h3 id="performDeleteOnModel"><a href="#performDeleteOnModel" class="headerlink" title="performDeleteOnModel"></a>performDeleteOnModel</h3><p>SoftDeletes 这个 trait 会重载 <code>performDeleteOnModel</code> 函数，它将不会调用 <code>Eloquent Builder</code> 的 <code>delete</code> 方法，而是采用更新操作：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div><div class="line">15</div><div class="line">16</div><div class="line">17</div><div class="line">18</div><div class="line">19</div><div class="line">20</div><div class="line">21</div><div class="line">22</div><div class="line">23</div><div class="line">24</div><div class="line">25</div><div class="line">26</div><div class="line">27</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">protected</span> <span class="function"><span class="keyword">function</span> <span class="title">performDeleteOnModel</span><span class="params">()</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">if</span> (<span class="keyword">$this</span>->forceDeleting) {</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->newQueryWithoutScopes()->where(<span class="keyword">$this</span>->getKeyName(), <span class="keyword">$this</span>->getKey())->forceDelete();</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->runSoftDelete();</div><div class="line">}</div><div class="line"></div><div class="line"><span class="keyword">protected</span> <span class="function"><span class="keyword">function</span> <span class="title">runSoftDelete</span><span class="params">()</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> $query = <span class="keyword">$this</span>->newQueryWithoutScopes()->where(<span class="keyword">$this</span>->getKeyName(), <span class="keyword">$this</span>->getKey());</div><div class="line"></div><div class="line"> $time = <span class="keyword">$this</span>->freshTimestamp();</div><div class="line"></div><div class="line"> $columns = [<span class="keyword">$this</span>->getDeletedAtColumn() => <span class="keyword">$this</span>->fromDateTime($time)];</div><div class="line"></div><div class="line"> <span class="keyword">$this</span>->{<span class="keyword">$this</span>->getDeletedAtColumn()} = $time;</div><div class="line"></div><div class="line"> <span class="keyword">if</span> (<span class="keyword">$this</span>->timestamps) {</div><div class="line"> <span class="keyword">$this</span>->{<span class="keyword">$this</span>->getUpdatedAtColumn()} = $time;</div><div class="line"></div><div class="line"> $columns[<span class="keyword">$this</span>->getUpdatedAtColumn()] = <span class="keyword">$this</span>->fromDateTime($time);</div><div class="line"> }</div><div class="line"></div><div class="line"> $query->update($columns);</div><div class="line">}</div></pre></td></tr></table></figure>
<p>删除操作不仅更新了 <code>deleted_at</code>，还更新了 <code>updated_at</code> 字段。</p>
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<h2 id="前言"><a href="#前言" class="headerlink" title="前言"></a>前言</h2><p>前面几个博客向大家介绍了查询构造器的原理与源码，然而查询构造器更多是为 <code>Eloquent Model</code> 服务的，我们对数据库操作更加方便的是使用 <code>Eloquent Model</code>。 本篇文章将会大家介绍 <code>Model</code> 的一些特性原理。</p>
<h2 id="Eloquent-Model-修改器"><a href="#Eloquent-Model-修改器" class="headerlink" title="Eloquent Model 修改器"></a>Eloquent Model 修改器</h2><p>当我们在 <code>Eloquent</code> 模型实例中设置某些属性值的时候，修改器允许对 <code>Eloquent</code> 属性值进行格式化。如果对修改器不熟悉，请参考官方文档：<a href="https://d.laravel-china.org/docs/5.5/eloquent-mutators" target="_blank" rel="external">Eloquent： 修改器</a></p>
<p>下面先看看修改器的原理：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div><div class="line">15</div><div class="line">16</div><div class="line">17</div><div class="line">18</div><div class="line">19</div><div class="line">20</div><div class="line">21</div><div class="line">22</div><div class="line">23</div><div class="line">24</div><div class="line">25</div><div class="line">26</div><div class="line">27</div><div class="line">28</div><div class="line">29</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">offsetSet</span><span class="params">($offset, $value)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">$this</span>->setAttribute($offset, $value);</div><div class="line">}</div><div class="line"></div><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">setAttribute</span><span class="params">($key, $value)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">if</span> (<span class="keyword">$this</span>->hasSetMutator($key)) {</div><div class="line"> $method = <span class="string">'set'</span>.Str::studly($key).<span class="string">'Attribute'</span>;</div><div class="line"></div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->{$method}($value);</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">elseif</span> ($value && <span class="keyword">$this</span>->isDateAttribute($key)) {</div><div class="line"> $value = <span class="keyword">$this</span>->fromDateTime($value);</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">if</span> (<span class="keyword">$this</span>->isJsonCastable($key) && ! is_null($value)) {</div><div class="line"> $value = <span class="keyword">$this</span>->castAttributeAsJson($key, $value);</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">if</span> (Str::contains($key, <span class="string">'->'</span>)) {</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->fillJsonAttribute($key, $value);</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">$this</span>->attributes[$key] = $value;</div><div class="line"></div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>;</div><div class="line">}</div></pre></td></tr></table></figure>
<h3 id="自定义修改器"><a href="#自定义修改器" class="headerlink" title="自定义修改器"></a>自定义修改器</h3><p>当我们为 <code>model</code> 的成员变量赋值的时候，就会调用 <code>offsetSet</code> 函数，进而运行 <code>setAttribute</code> 函数，在这个函数中第一个检查的就是是否存在预处理函数：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">hasSetMutator</span><span class="params">($key)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">return</span> method_exists(<span class="keyword">$this</span>, <span class="string">'set'</span>.Str::studly($key).<span class="string">'Attribute'</span>);</div><div class="line">}</div></pre></td></tr></table></figure>
<p>如果存在该函数，就会直接调用自定义修改器。</p>
<h3 id="日期转换器"><a href="#日期转换器" class="headerlink" title="日期转换器"></a>日期转换器</h3><p>接着如果没有自定义修改器的话，还会检查当前更新的成员变量是否是日期属性：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div><div class="line">15</div><div class="line">16</div><div class="line">17</div><div class="line">18</div><div class="line">19</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">protected</span> <span class="function"><span class="keyword">function</span> <span class="title">isDateAttribute</span><span class="params">($key)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">return</span> in_array($key, <span class="keyword">$this</span>->getDates()) ||</div><div class="line"> <span class="keyword">$this</span>->isDateCastable($key);</div><div class="line">}</div><div class="line"></div><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">getDates</span><span class="params">()</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> $defaults = [<span class="keyword">static</span>::CREATED_AT, <span class="keyword">static</span>::UPDATED_AT];</div><div class="line"></div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->usesTimestamps()</div><div class="line"> ? array_unique(array_merge(<span class="keyword">$this</span>->dates, $defaults))</div><div class="line"> : <span class="keyword">$this</span>->dates;</div><div class="line">}</div><div class="line"></div><div class="line"><span class="keyword">protected</span> <span class="function"><span class="keyword">function</span> <span class="title">isDateCastable</span><span class="params">($key)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->hasCast($key, [<span class="string">'date'</span>, <span class="string">'datetime'</span>]);</div><div class="line">}</div></pre></td></tr></table></figure>
<p>字段的时间属性有两种设置方法，一种是设置 <code>$dates</code> 属性：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">protected</span> $dates = [<span class="string">'date_attr'</span>];</div></pre></td></tr></table></figure>
<p>还有一种方法是设置 <code>cast</code> 数组：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">protected</span> $casts = [<span class="string">'date_attr'</span> => <span class="string">'date'</span>];</div></pre></td></tr></table></figure>
<p>只要是时间属性的字段，无论是什么类型的值，<code>laravel</code> 都会自动将其转化为数据库的时间格式。数据库的时间格式设置是 <code>dateFormat</code> 成员变量，不设置的时候，默认的时间格式为 `Y-m-d H:i:s’:</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">protected</span> $dateFormat = [<span class="string">'U'</span>];</div><div class="line"></div><div class="line"><span class="keyword">protected</span> $dateFormat = [<span class="string">'Y-m-d H:i:s'</span>];</div></pre></td></tr></table></figure>
<p>当数据库对应的字段是时间类型时，为其赋值就可以非常灵活。我们可以赋值 <code>Carbon</code> 类型、<code>DateTime</code> 类型、数字类型、字符串等等：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div><div class="line">15</div><div class="line">16</div><div class="line">17</div><div class="line">18</div><div class="line">19</div><div class="line">20</div><div class="line">21</div><div class="line">22</div><div class="line">23</div><div class="line">24</div><div class="line">25</div><div class="line">26</div><div class="line">27</div><div class="line">28</div><div class="line">29</div><div class="line">30</div><div class="line">31</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">fromDateTime</span><span class="params">($value)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">return</span> is_null($value) ? $value : <span class="keyword">$this</span>->asDateTime($value)->format(</div><div class="line"> <span class="keyword">$this</span>->getDateFormat()</div><div class="line"> );</div><div class="line">}</div><div class="line"></div><div class="line"><span class="keyword">protected</span> <span class="function"><span class="keyword">function</span> <span class="title">asDateTime</span><span class="params">($value)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">if</span> ($value <span class="keyword">instanceof</span> Carbon) {</div><div class="line"> <span class="keyword">return</span> $value;</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">if</span> ($value <span class="keyword">instanceof</span> DateTimeInterface) {</div><div class="line"> <span class="keyword">return</span> <span class="keyword">new</span> Carbon(</div><div class="line"> $value->format(<span class="string">'Y-m-d H:i:s.u'</span>), $value->getTimezone()</div><div class="line"> );</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">if</span> (is_numeric($value)) {</div><div class="line"> <span class="keyword">return</span> Carbon::createFromTimestamp($value);</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">if</span> (<span class="keyword">$this</span>->isStandardDateFormat($value)) {</div><div class="line"> <span class="keyword">return</span> Carbon::createFromFormat(<span class="string">'Y-m-d'</span>, $value)->startOfDay();</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">return</span> Carbon::createFromFormat(</div><div class="line"> <span class="keyword">$this</span>->getDateFormat(), $value</div><div class="line"> );</div><div class="line">}</div></pre></td></tr></table></figure>
<h3 id="json-转换器"><a href="#json-转换器" class="headerlink" title="json 转换器"></a>json 转换器</h3><p>接下来，如果该变量被设置为 <code>array</code>、<code>json</code> 等属性，那么其将会转化为 <code>json</code> 类型。</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">protected</span> <span class="function"><span class="keyword">function</span> <span class="title">isJsonCastable</span><span class="params">($key)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->hasCast($key, [<span class="string">'array'</span>, <span class="string">'json'</span>, <span class="string">'object'</span>, <span class="string">'collection'</span>]);</div><div class="line">}</div><div class="line"></div><div class="line"><span class="keyword">protected</span> <span class="function"><span class="keyword">function</span> <span class="title">asJson</span><span class="params">($value)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">return</span> json_encode($value);</div><div class="line">}</div></pre></td></tr></table></figure>
<h2 id="Eloquent-Model-访问器"><a href="#Eloquent-Model-访问器" class="headerlink" title="Eloquent Model 访问器"></a>Eloquent Model 访问器</h2><p>相比较修改器来说，访问器的适用情景会更加多。例如，我们经常把一些关于类型的字段设置为 <code>1</code>、<code>2</code>、<code>3</code> 等等，例如用户数据表中用户性别字段，<code>1</code> 代表男，<code>2</code> 代表女，很多时候我们取出这些值之后必然要经过转换，然后再显示出来。这时候就需要定义访问器。</p>
<p>访问器的源码：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div><div class="line">15</div><div class="line">16</div><div class="line">17</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">getAttribute</span><span class="params">($key)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">if</span> (! $key) {</div><div class="line"> <span class="keyword">return</span>;</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">if</span> (array_key_exists($key, <span class="keyword">$this</span>->attributes) ||</div><div class="line"> <span class="keyword">$this</span>->hasGetMutator($key)) {</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->getAttributeValue($key);</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">if</span> (method_exists(<span class="keyword">self</span>::class, $key)) {</div><div class="line"> <span class="keyword">return</span>;</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->getRelationValue($key);</div><div class="line">}</div></pre></td></tr></table></figure>
<p>可以看到，当我们访问数据库对象的成员变量的时候，大致可以分为两类：属性值与关系对象。关系对象我们以后再详细来说，本文中先说关于属性的访问。</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div><div class="line">15</div><div class="line">16</div><div class="line">17</div><div class="line">18</div><div class="line">19</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">getAttributeValue</span><span class="params">($key)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> $value = <span class="keyword">$this</span>->getAttributeFromArray($key);</div><div class="line"></div><div class="line"> <span class="keyword">if</span> (<span class="keyword">$this</span>->hasGetMutator($key)) {</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->mutateAttribute($key, $value);</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">if</span> (<span class="keyword">$this</span>->hasCast($key)) {</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->castAttribute($key, $value);</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">if</span> (in_array($key, <span class="keyword">$this</span>->getDates()) &&</div><div class="line"> ! is_null($value)) {</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->asDateTime($value);</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">return</span> $value;</div><div class="line">}</div></pre></td></tr></table></figure>
<p>与修改器类似，访问器也由三部分构成：自定义访问器、日期访问器、类型访问器。</p>
<h3 id="获取原始值"><a href="#获取原始值" class="headerlink" title="获取原始值"></a>获取原始值</h3><p>访问器的第一步就是从成员变量 <code>attributes</code> 中获取原始的字段值，一般指的是存在数据库的值。有的时候，我们要取的属性并不在 <code>attributes</code> 中，这时候就会返回 <code>null</code>。</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">protected</span> <span class="function"><span class="keyword">function</span> <span class="title">getAttributeFromArray</span><span class="params">($key)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">if</span> (<span class="keyword">isset</span>(<span class="keyword">$this</span>->attributes[$key])) {</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->attributes[$key];</div><div class="line"> }</div><div class="line">}</div></pre></td></tr></table></figure>
<h3 id="自定义访问器"><a href="#自定义访问器" class="headerlink" title="自定义访问器"></a>自定义访问器</h3><p>如果定义了访问器，那么就会调用访问器，获取返回值：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">hasGetMutator</span><span class="params">($key)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">return</span> method_exists(<span class="keyword">$this</span>, <span class="string">'get'</span>.Str::studly($key).<span class="string">'Attribute'</span>);</div><div class="line">}</div><div class="line"></div><div class="line"><span class="keyword">protected</span> <span class="function"><span class="keyword">function</span> <span class="title">mutateAttribute</span><span class="params">($key, $value)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->{<span class="string">'get'</span>.Str::studly($key).<span class="string">'Attribute'</span>}($value);</div><div class="line">}</div></pre></td></tr></table></figure>
<h3 id="类型转换"><a href="#类型转换" class="headerlink" title="类型转换"></a>类型转换</h3><p>若我们在成员变量 <code>$casts</code> 数组中为属性定义了类型转换，那么就要进行类型转换：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div><div class="line">15</div><div class="line">16</div><div class="line">17</div><div class="line">18</div><div class="line">19</div><div class="line">20</div><div class="line">21</div><div class="line">22</div><div class="line">23</div><div class="line">24</div><div class="line">25</div><div class="line">26</div><div class="line">27</div><div class="line">28</div><div class="line">29</div><div class="line">30</div><div class="line">31</div><div class="line">32</div><div class="line">33</div><div class="line">34</div><div class="line">35</div><div class="line">36</div><div class="line">37</div><div class="line">38</div><div class="line">39</div><div class="line">40</div><div class="line">41</div><div class="line">42</div><div class="line">43</div><div class="line">44</div><div class="line">45</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">hasCast</span><span class="params">($key, $types = null)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">if</span> (array_key_exists($key, <span class="keyword">$this</span>->getCasts())) {</div><div class="line"> <span class="keyword">return</span> $types ? in_array(<span class="keyword">$this</span>->getCastType($key), (<span class="keyword">array</span>) $types, <span class="keyword">true</span>) : <span class="keyword">true</span>;</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">return</span> <span class="keyword">false</span>;</div><div class="line">}</div><div class="line"></div><div class="line"><span class="keyword">protected</span> <span class="function"><span class="keyword">function</span> <span class="title">castAttribute</span><span class="params">($key, $value)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">if</span> (is_null($value)) {</div><div class="line"> <span class="keyword">return</span> $value;</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">switch</span> (<span class="keyword">$this</span>->getCastType($key)) {</div><div class="line"> <span class="keyword">case</span> <span class="string">'int'</span>:</div><div class="line"> <span class="keyword">case</span> <span class="string">'integer'</span>:</div><div class="line"> <span class="keyword">return</span> (int) $value;</div><div class="line"> <span class="keyword">case</span> <span class="string">'real'</span>:</div><div class="line"> <span class="keyword">case</span> <span class="string">'float'</span>:</div><div class="line"> <span class="keyword">case</span> <span class="string">'double'</span>:</div><div class="line"> <span class="keyword">return</span> (float) $value;</div><div class="line"> <span class="keyword">case</span> <span class="string">'string'</span>:</div><div class="line"> <span class="keyword">return</span> (string) $value;</div><div class="line"> <span class="keyword">case</span> <span class="string">'bool'</span>:</div><div class="line"> <span class="keyword">case</span> <span class="string">'boolean'</span>:</div><div class="line"> <span class="keyword">return</span> (bool) $value;</div><div class="line"> <span class="keyword">case</span> <span class="string">'object'</span>:</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->fromJson($value, <span class="keyword">true</span>);</div><div class="line"> <span class="keyword">case</span> <span class="string">'array'</span>:</div><div class="line"> <span class="keyword">case</span> <span class="string">'json'</span>:</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->fromJson($value);</div><div class="line"> <span class="keyword">case</span> <span class="string">'collection'</span>:</div><div class="line"> <span class="keyword">return</span> <span class="keyword">new</span> BaseCollection(<span class="keyword">$this</span>->fromJson($value));</div><div class="line"> <span class="keyword">case</span> <span class="string">'date'</span>:</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->asDate($value);</div><div class="line"> <span class="keyword">case</span> <span class="string">'datetime'</span>:</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->asDateTime($value);</div><div class="line"> <span class="keyword">case</span> <span class="string">'timestamp'</span>:</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->asTimestamp($value);</div><div class="line"> <span class="keyword">default</span>:</div><div class="line"> <span class="keyword">return</span> $value;</div><div class="line"> }</div><div class="line">}</div></pre></td></tr></table></figure>
<h3 id="日期转换"><a href="#日期转换" class="headerlink" title="日期转换"></a>日期转换</h3><p>若当前属性是 <code>CREATED_AT</code>、<code>UPDATED_AT</code> 或者被存入成员变量 <code>dates</code> 中，那么就要进行日期转换。日期转换函数 <code>asDateTime</code> 可以查看上一节中的内容。</p>
<h2 id="Eloquent-Model-数组转化"><a href="#Eloquent-Model-数组转化" class="headerlink" title="Eloquent Model 数组转化"></a>Eloquent Model 数组转化</h2><p>在使用数据库对象中，我们经常使用 <code>toArray</code> 函数，它可以将从数据库中取出的所有属性和关系模型转化为数组：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div><div class="line">15</div><div class="line">16</div><div class="line">17</div><div class="line">18</div><div class="line">19</div><div class="line">20</div><div class="line">21</div><div class="line">22</div><div class="line">23</div><div class="line">24</div><div class="line">25</div><div class="line">26</div><div class="line">27</div><div class="line">28</div><div class="line">29</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">toArray</span><span class="params">()</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">return</span> array_merge(<span class="keyword">$this</span>->attributesToArray(), <span class="keyword">$this</span>->relationsToArray());</div><div class="line">}</div><div class="line">``` </div><div class="line"></div><div class="line">本文中只介绍属性转化为数组的部分：</div><div class="line"></div><div class="line">```php</div><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">attributesToArray</span><span class="params">()</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> $attributes = <span class="keyword">$this</span>->addDateAttributesToArray(</div><div class="line"> $attributes = <span class="keyword">$this</span>->getArrayableAttributes()</div><div class="line"> );</div><div class="line"></div><div class="line"> $attributes = <span class="keyword">$this</span>->addMutatedAttributesToArray(</div><div class="line"> $attributes, $mutatedAttributes = <span class="keyword">$this</span>->getMutatedAttributes()</div><div class="line"> );</div><div class="line"> </div><div class="line"> $attributes = <span class="keyword">$this</span>->addCastAttributesToArray(</div><div class="line"> $attributes, $mutatedAttributes</div><div class="line"> );</div><div class="line"></div><div class="line"> <span class="keyword">foreach</span> (<span class="keyword">$this</span>->getArrayableAppends() <span class="keyword">as</span> $key) {</div><div class="line"> $attributes[$key] = <span class="keyword">$this</span>->mutateAttributeForArray($key, <span class="keyword">null</span>);</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">return</span> $attributes;</div><div class="line">}</div></pre></td></tr></table></figure>
<p>与访问器与修改器类似，需要转为数组的元素有日期类型、自定义访问器、类型转换，我们接下来一个个看：</p>
<h3 id="getArrayableAttributes-原始值获取"><a href="#getArrayableAttributes-原始值获取" class="headerlink" title="getArrayableAttributes 原始值获取"></a>getArrayableAttributes 原始值获取</h3><p>首先我们要从成员变量 <code>attributes</code> 数组中获取原始值：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div><div class="line">15</div><div class="line">16</div><div class="line">17</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">protected</span> <span class="function"><span class="keyword">function</span> <span class="title">getArrayableAttributes</span><span class="params">()</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->getArrayableItems(<span class="keyword">$this</span>->attributes);</div><div class="line">}</div><div class="line"></div><div class="line"><span class="keyword">protected</span> <span class="function"><span class="keyword">function</span> <span class="title">getArrayableItems</span><span class="params">(array $values)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">if</span> (count(<span class="keyword">$this</span>->getVisible()) > <span class="number">0</span>) {</div><div class="line"> $values = array_intersect_key($values, array_flip(<span class="keyword">$this</span>->getVisible()));</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">if</span> (count(<span class="keyword">$this</span>->getHidden()) > <span class="number">0</span>) {</div><div class="line"> $values = array_diff_key($values, array_flip(<span class="keyword">$this</span>->getHidden()));</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">return</span> $values;</div><div class="line">}</div></pre></td></tr></table></figure>
<p>我们还可以为数据库对象设置可见元素 <code>$visible</code> 与隐藏元素 <code>$hidden</code>，这两个变量会控制 <code>toArray</code> 可转化的元素属性。</p>
<h3 id="日期转换-1"><a href="#日期转换-1" class="headerlink" title="日期转换"></a>日期转换</h3><figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div><div class="line">15</div><div class="line">16</div><div class="line">17</div><div class="line">18</div><div class="line">19</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">protected</span> <span class="function"><span class="keyword">function</span> <span class="title">addDateAttributesToArray</span><span class="params">(array $attributes)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">foreach</span> (<span class="keyword">$this</span>->getDates() <span class="keyword">as</span> $key) {</div><div class="line"> <span class="keyword">if</span> (! <span class="keyword">isset</span>($attributes[$key])) {</div><div class="line"> <span class="keyword">continue</span>;</div><div class="line"> }</div><div class="line"></div><div class="line"> $attributes[$key] = <span class="keyword">$this</span>->serializeDate(</div><div class="line"> <span class="keyword">$this</span>->asDateTime($attributes[$key])</div><div class="line"> );</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">return</span> $attributes;</div><div class="line">}</div><div class="line"></div><div class="line"><span class="keyword">protected</span> <span class="function"><span class="keyword">function</span> <span class="title">serializeDate</span><span class="params">(DateTimeInterface $date)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">return</span> $date->format(<span class="keyword">$this</span>->getDateFormat());</div><div class="line">}</div></pre></td></tr></table></figure>
<h3 id="自定义访问器转换"><a href="#自定义访问器转换" class="headerlink" title="自定义访问器转换"></a>自定义访问器转换</h3><p>定义了自定义访问器的属性，会调用访问器函数来覆盖原有的属性值，首先我们需要获取所有的自定义访问器变量：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div><div class="line">15</div><div class="line">16</div><div class="line">17</div><div class="line">18</div><div class="line">19</div><div class="line">20</div><div class="line">21</div><div class="line">22</div><div class="line">23</div><div class="line">24</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">getMutatedAttributes</span><span class="params">()</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> $class = <span class="keyword">static</span>::class;</div><div class="line"></div><div class="line"> <span class="keyword">if</span> (! <span class="keyword">isset</span>(<span class="keyword">static</span>::$mutatorCache[$class])) {</div><div class="line"> <span class="keyword">static</span>::cacheMutatedAttributes($class);</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">return</span> <span class="keyword">static</span>::$mutatorCache[$class];</div><div class="line">}</div><div class="line"></div><div class="line"><span class="keyword">public</span> <span class="keyword">static</span> <span class="function"><span class="keyword">function</span> <span class="title">cacheMutatedAttributes</span><span class="params">($class)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">static</span>::$mutatorCache[$class] = collect(<span class="keyword">static</span>::getMutatorMethods($class))->map(<span class="function"><span class="keyword">function</span> <span class="params">($match)</span> </span>{</div><div class="line"> <span class="keyword">return</span> lcfirst(<span class="keyword">static</span>::$snakeAttributes ? Str::snake($match) : $match);</div><div class="line"> })->all();</div><div class="line">}</div><div class="line"></div><div class="line"><span class="keyword">protected</span> <span class="keyword">static</span> <span class="function"><span class="keyword">function</span> <span class="title">getMutatorMethods</span><span class="params">($class)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> preg_match_all(<span class="string">'/(?<=^|;)get([^;]+?)Attribute(;|$)/'</span>, implode(<span class="string">';'</span>, get_class_methods($class)), $matches);</div><div class="line"></div><div class="line"> <span class="keyword">return</span> $matches[<span class="number">1</span>];</div><div class="line">}</div></pre></td></tr></table></figure>
<p>可以看到，函数用 <code>get_class_methods</code> 获取类内所有的函数，并筛选出符合 <code>get...Attribute</code> 的函数，获得自定义的访问器变量，并缓存到 <code>mutatorCache</code> 中。</p>
<p>接着将会利用自定义访问器变量替换原始值：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div><div class="line">15</div><div class="line">16</div><div class="line">17</div><div class="line">18</div><div class="line">19</div><div class="line">20</div><div class="line">21</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">protected</span> <span class="function"><span class="keyword">function</span> <span class="title">addMutatedAttributesToArray</span><span class="params">(array $attributes, array $mutatedAttributes)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">foreach</span> ($mutatedAttributes <span class="keyword">as</span> $key) {</div><div class="line"> <span class="keyword">if</span> (! array_key_exists($key, $attributes)) {</div><div class="line"> <span class="keyword">continue</span>;</div><div class="line"> }</div><div class="line"></div><div class="line"> $attributes[$key] = <span class="keyword">$this</span>->mutateAttributeForArray(</div><div class="line"> $key, $attributes[$key]</div><div class="line"> );</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">return</span> $attributes;</div><div class="line">}</div><div class="line"></div><div class="line"><span class="keyword">protected</span> <span class="function"><span class="keyword">function</span> <span class="title">mutateAttributeForArray</span><span class="params">($key, $value)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> $value = <span class="keyword">$this</span>->mutateAttribute($key, $value);</div><div class="line"></div><div class="line"> <span class="keyword">return</span> $value <span class="keyword">instanceof</span> Arrayable ? $value->toArray() : $value;</div><div class="line">}</div></pre></td></tr></table></figure>
<h3 id="cast-类型转换"><a href="#cast-类型转换" class="headerlink" title="cast 类型转换"></a>cast 类型转换</h3><p>被定义在 <code>cast</code> 数组中的变量也要进行数组转换，调用的方法和访问器相同，也是 <code>castAttribute</code>，如果是时间类型，还要按照时间格式来转换：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div><div class="line">15</div><div class="line">16</div><div class="line">17</div><div class="line">18</div><div class="line">19</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">protected</span> <span class="function"><span class="keyword">function</span> <span class="title">addCastAttributesToArray</span><span class="params">(array $attributes, array $mutatedAttributes)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">foreach</span> (<span class="keyword">$this</span>->getCasts() <span class="keyword">as</span> $key => $value) {</div><div class="line"> <span class="keyword">if</span> (! array_key_exists($key, $attributes) || in_array($key, $mutatedAttributes)) {</div><div class="line"> <span class="keyword">continue</span>;</div><div class="line"> }</div><div class="line"></div><div class="line"> $attributes[$key] = <span class="keyword">$this</span>->castAttribute(</div><div class="line"> $key, $attributes[$key]</div><div class="line"> );</div><div class="line"></div><div class="line"> <span class="keyword">if</span> ($attributes[$key] &&</div><div class="line"> ($value === <span class="string">'date'</span> || $value === <span class="string">'datetime'</span>)) {</div><div class="line"> $attributes[$key] = <span class="keyword">$this</span>->serializeDate($attributes[$key]);</div><div class="line"> }</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">return</span> $attributes;</div><div class="line">}</div></pre></td></tr></table></figure>
<h3 id="appends-额外属性添加"><a href="#appends-额外属性添加" class="headerlink" title="appends 额外属性添加"></a>appends 额外属性添加</h3><p><code>toArray()</code> 还会将我们定义在 <code>appends</code> 变量中的属性一起进行数组转换，但是注意被放入 <code>appends</code> 成员变量数组中的属性需要有自定义访问器函数：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">protected</span> <span class="function"><span class="keyword">function</span> <span class="title">getArrayableAppends</span><span class="params">()</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">if</span> (! count(<span class="keyword">$this</span>->appends)) {</div><div class="line"> <span class="keyword">return</span> [];</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->getArrayableItems(</div><div class="line"> array_combine(<span class="keyword">$this</span>->appends, <span class="keyword">$this</span>->appends)</div><div class="line"> );</div><div class="line">}</div></pre></td></tr></table></figure>
<h2 id="查询作用域"><a href="#查询作用域" class="headerlink" title="查询作用域"></a>查询作用域</h2><p>查询作用域分为全局作用域与本地作用域。全局作用域不需要手动调用，由程序在每次的查询中自动加载，本地作用域需要在查询的时候进行手动调用。官方文档：<a href="https://d.laravel-china.org/docs/5.5/eloquent#query-scopes" target="_blank" rel="external">查询作用域</a></p>
<h3 id="全局作用域"><a href="#全局作用域" class="headerlink" title="全局作用域"></a>全局作用域</h3><p>一般全局作用域需要定义一个实现 <code>Illuminate\Database\Eloquent\Scope</code> 接口的类，该接口要求你实现一个方法：<code>apply</code>。需要的话可以在 <code>apply</code> 方法中添加 <code>where</code> 条件到查询。</p>
<p>要将全局作用域分配给模型，需要重写给定模型的 <code>boot</code> 方法并使用 <code>addGlobalScope</code> 方法。</p>
<p>另外，我们还可以向 <code>addGlobalScope</code> 中添加匿名函数实现匿名全局作用域。</p>
<p>我们先看看源码：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="keyword">static</span> <span class="function"><span class="keyword">function</span> <span class="title">addGlobalScope</span><span class="params">($scope, Closure $implementation = null)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">if</span> (is_string($scope) && ! is_null($implementation)) {</div><div class="line"> <span class="keyword">return</span> <span class="keyword">static</span>::$globalScopes[<span class="keyword">static</span>::class][$scope] = $implementation;</div><div class="line"> } <span class="keyword">elseif</span> ($scope <span class="keyword">instanceof</span> Closure) {</div><div class="line"> <span class="keyword">return</span> <span class="keyword">static</span>::$globalScopes[<span class="keyword">static</span>::class][spl_object_hash($scope)] = $scope;</div><div class="line"> } <span class="keyword">elseif</span> ($scope <span class="keyword">instanceof</span> Scope) {</div><div class="line"> <span class="keyword">return</span> <span class="keyword">static</span>::$globalScopes[<span class="keyword">static</span>::class][get_class($scope)] = $scope;</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">throw</span> <span class="keyword">new</span> InvalidArgumentException(<span class="string">'Global scope must be an instance of Closure or Scope.'</span>);</div><div class="line">}</div></pre></td></tr></table></figure>
<p>可以看到，全局作用域使用的是全局的静态变量 <code>globalScopes</code>，该变量保存着所有数据库对象的全局作用域。</p>
<p><code>Eloquent\Model</code> 类并不负责查询功能，相关功能由 <code>Eloquent\Builder</code> 负责，因此每次查询都会间接调用 <code>Eloquent\Builder</code> 类。</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">__call</span><span class="params">($method, $parameters)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">if</span> (in_array($method, [<span class="string">'increment'</span>, <span class="string">'decrement'</span>])) {</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->$method(...$parameters);</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">try</span> {</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->newQuery()->$method(...$parameters);</div><div class="line"> } <span class="keyword">catch</span> (BadMethodCallException $e) {</div><div class="line"> <span class="keyword">throw</span> <span class="keyword">new</span> BadMethodCallException(</div><div class="line"> sprintf(<span class="string">'Call to undefined method %s::%s()'</span>, get_class(<span class="keyword">$this</span>), $method)</div><div class="line"> );</div><div class="line"> }</div><div class="line">}</div></pre></td></tr></table></figure>
<p>创建新的 <code>Eloquent\Builder</code> 类需要 <code>newQuery</code> 函数：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div><div class="line">15</div><div class="line">16</div><div class="line">17</div><div class="line">18</div><div class="line">19</div><div class="line">20</div><div class="line">21</div><div class="line">22</div><div class="line">23</div><div class="line">24</div><div class="line">25</div><div class="line">26</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">newQuery</span><span class="params">()</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> $builder = <span class="keyword">$this</span>->newQueryWithoutScopes();</div><div class="line"></div><div class="line"> <span class="keyword">foreach</span> (<span class="keyword">$this</span>->getGlobalScopes() <span class="keyword">as</span> $identifier => $scope) {</div><div class="line"> $builder->withGlobalScope($identifier, $scope);</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">return</span> $builder;</div><div class="line">}</div><div class="line"></div><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">getGlobalScopes</span><span class="params">()</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">return</span> Arr::get(<span class="keyword">static</span>::$globalScopes, <span class="keyword">static</span>::class, []);</div><div class="line">}</div><div class="line"></div><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">withGlobalScope</span><span class="params">($identifier, $scope)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">$this</span>->scopes[$identifier] = $scope;</div><div class="line"></div><div class="line"> <span class="keyword">if</span> (method_exists($scope, <span class="string">'extend'</span>)) {</div><div class="line"> $scope->extend(<span class="keyword">$this</span>);</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>;</div><div class="line">}</div></pre></td></tr></table></figure>
<p><code>newQuery</code> 函数为 <code>Eloquent\builder</code> 加载全局作用域，这样静态变量 <code>globalScopes</code> 的值就会被赋到 <code>Eloquent\builder</code> 的 <code>scopes</code> 成员变量中。</p>
<p>当我们使用 <code>get()</code> 函数获取数据库数据的时候，也需要借助魔术方法调用 <code>Illuminate\Database\Eloquent\Builder</code> 类的 <code>get</code> 函数：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">get</span><span class="params">($columns = [<span class="string">'*'</span>])</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> $builder = <span class="keyword">$this</span>->applyScopes();</div><div class="line"></div><div class="line"> <span class="keyword">if</span> (count($models = $builder->getModels($columns)) > <span class="number">0</span>) {</div><div class="line"> $models = $builder->eagerLoadRelations($models);</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">return</span> $builder->getModel()->newCollection($models);</div><div class="line">}</div></pre></td></tr></table></figure>
<p>调用 <code>applyScopes</code> 函数加载所有的全局作用域：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div><div class="line">15</div><div class="line">16</div><div class="line">17</div><div class="line">18</div><div class="line">19</div><div class="line">20</div><div class="line">21</div><div class="line">22</div><div class="line">23</div><div class="line">24</div><div class="line">25</div><div class="line">26</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">applyScopes</span><span class="params">()</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">if</span> (! <span class="keyword">$this</span>->scopes) {</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>;</div><div class="line"> }</div><div class="line"></div><div class="line"> $builder = <span class="keyword">clone</span> <span class="keyword">$this</span>;</div><div class="line"></div><div class="line"> <span class="keyword">foreach</span> (<span class="keyword">$this</span>->scopes <span class="keyword">as</span> $identifier => $scope) {</div><div class="line"> <span class="keyword">if</span> (! <span class="keyword">isset</span>($builder->scopes[$identifier])) {</div><div class="line"> <span class="keyword">continue</span>;</div><div class="line"> }</div><div class="line"></div><div class="line"> $builder->callScope(<span class="function"><span class="keyword">function</span> <span class="params">(Builder $builder)</span> <span class="title">use</span> <span class="params">($scope)</span> </span>{</div><div class="line"> <span class="keyword">if</span> ($scope <span class="keyword">instanceof</span> Closure) {</div><div class="line"> $scope($builder);</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">if</span> ($scope <span class="keyword">instanceof</span> Scope) {</div><div class="line"> $scope->apply($builder, <span class="keyword">$this</span>->getModel());</div><div class="line"> }</div><div class="line"> });</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">return</span> $builder;</div><div class="line">}</div></pre></td></tr></table></figure>
<p>可以看到，<code>builder</code> 查询类会通过 <code>callScope</code> 加载全局作用域的查询条件。</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div><div class="line">15</div><div class="line">16</div><div class="line">17</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">protected</span> <span class="function"><span class="keyword">function</span> <span class="title">callScope</span><span class="params">(callable $scope, $parameters = [])</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> array_unshift($parameters, <span class="keyword">$this</span>);</div><div class="line"></div><div class="line"> $query = <span class="keyword">$this</span>->getQuery();</div><div class="line"></div><div class="line"> $originalWhereCount = is_null($query->wheres)</div><div class="line"> ? <span class="number">0</span> : count($query->wheres);</div><div class="line"></div><div class="line"> $result = $scope(...array_values($parameters)) ?? <span class="keyword">$this</span>;</div><div class="line"></div><div class="line"> <span class="keyword">if</span> (count((<span class="keyword">array</span>) $query->wheres) > $originalWhereCount) {</div><div class="line"> <span class="keyword">$this</span>->addNewWheresWithinGroup($query, $originalWhereCount);</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">return</span> $result;</div><div class="line">}</div></pre></td></tr></table></figure>
<p><code>callScope</code> 函数首先会获取更加底层的 <code>Query\builder</code>，更新 <code>query\bulid</code> 的 <code>where</code> 条件。</p>
<p><code>addNewWheresWithinGroup</code> 这个函数很重要，它为 <code>Query\builder</code> 提供 <code>nest</code> 类型的 <code>where</code> 条件：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div><div class="line">15</div><div class="line">16</div><div class="line">17</div><div class="line">18</div><div class="line">19</div><div class="line">20</div><div class="line">21</div><div class="line">22</div><div class="line">23</div><div class="line">24</div><div class="line">25</div><div class="line">26</div><div class="line">27</div><div class="line">28</div><div class="line">29</div><div class="line">30</div><div class="line">31</div><div class="line">32</div><div class="line">33</div><div class="line">34</div><div class="line">35</div><div class="line">36</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">protected</span> <span class="function"><span class="keyword">function</span> <span class="title">addNewWheresWithinGroup</span><span class="params">(QueryBuilder $query, $originalWhereCount)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> $allWheres = $query->wheres;</div><div class="line"></div><div class="line"> $query->wheres = [];</div><div class="line"></div><div class="line"> <span class="keyword">$this</span>->groupWhereSliceForScope(</div><div class="line"> $query, array_slice($allWheres, <span class="number">0</span>, $originalWhereCount)</div><div class="line"> );</div><div class="line"></div><div class="line"> <span class="keyword">$this</span>->groupWhereSliceForScope(</div><div class="line"> $query, array_slice($allWheres, $originalWhereCount)</div><div class="line"> );</div><div class="line">}</div><div class="line"></div><div class="line"><span class="keyword">protected</span> <span class="function"><span class="keyword">function</span> <span class="title">groupWhereSliceForScope</span><span class="params">(QueryBuilder $query, $whereSlice)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> $whereBooleans = collect($whereSlice)->pluck(<span class="string">'boolean'</span>);</div><div class="line"></div><div class="line"> <span class="keyword">if</span> ($whereBooleans->contains(<span class="string">'or'</span>)) {</div><div class="line"> $query->wheres[] = <span class="keyword">$this</span>->createNestedWhere(</div><div class="line"> $whereSlice, $whereBooleans->first()</div><div class="line"> );</div><div class="line"> } <span class="keyword">else</span> {</div><div class="line"> $query->wheres = array_merge($query->wheres, $whereSlice);</div><div class="line"> }</div><div class="line">}</div><div class="line"></div><div class="line"><span class="keyword">protected</span> <span class="function"><span class="keyword">function</span> <span class="title">createNestedWhere</span><span class="params">($whereSlice, $boolean = <span class="string">'and'</span>)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> $whereGroup = <span class="keyword">$this</span>->getQuery()->forNestedWhere();</div><div class="line"></div><div class="line"> $whereGroup->wheres = $whereSlice;</div><div class="line"></div><div class="line"> <span class="keyword">return</span> [<span class="string">'type'</span> => <span class="string">'Nested'</span>, <span class="string">'query'</span> => $whereGroup, <span class="string">'boolean'</span> => $boolean];</div><div class="line">}</div></pre></td></tr></table></figure>
<p>当我们在查询作用域中，所有的查询条件连接符都是 <code>and</code> 的时候，可以直接合并到 <code>where</code> 中。</p>
<p>如果我们在查询作用域中或者原查询条件写下了 <code>orWhere</code>、<code>orWhereColumn</code> 等等连接符为 <code>or</code> 的查询条件，那么就会利用 <code>createNestedWhere</code> 函数创建 <code>nest</code> 类型的 <code>where</code> 条件。这个 <code>where</code> 条件会包含查询作用域的所有查询条件，或者原查询的所有查询条件。</p>
<h3 id="本地作用域"><a href="#本地作用域" class="headerlink" title="本地作用域"></a>本地作用域</h3><p>全局作用域会自定加载到所有的查询条件当中，<code>laravel</code> 中还有本地作用域，只有在查询时调用才会生效。</p>
<p>本地作用域是由魔术方法 <code>__call</code> 实现的：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div><div class="line">15</div><div class="line">16</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">__call</span><span class="params">($method, $parameters)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> ...</div><div class="line"> </div><div class="line"> <span class="keyword">if</span> (method_exists(<span class="keyword">$this</span>->model, $scope = <span class="string">'scope'</span>.ucfirst($method))) {</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->callScope([<span class="keyword">$this</span>->model, $scope], $parameters);</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">if</span> (in_array($method, <span class="keyword">$this</span>->passthru)) {</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->toBase()->{$method}(...$parameters);</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">$this</span>->query->{$method}(...$parameters);</div><div class="line"></div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>;</div><div class="line">}</div></pre></td></tr></table></figure>
<h3 id="批量调用本地作用域"><a href="#批量调用本地作用域" class="headerlink" title="批量调用本地作用域"></a>批量调用本地作用域</h3><p><code>laravel</code> 还提供一个方法可以一次性调用多个本地作用域：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div></pre></td><td class="code"><pre><div class="line">$scopes = [</div><div class="line"> <span class="string">'published'</span>,</div><div class="line"> <span class="string">'category'</span> => <span class="string">'Laravel'</span>,</div><div class="line"> <span class="string">'framework'</span> => [<span class="string">'Laravel'</span>, <span class="string">'5.3'</span>],</div><div class="line">];</div><div class="line"></div><div class="line">(<span class="keyword">new</span> EloquentModelStub)->scopes($scopes);</div></pre></td></tr></table></figure>
<p>上面的写法会调用三个本地作用域，它们的参数是 <code>$scopes</code> 的值。</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div><div class="line">15</div><div class="line">16</div><div class="line">17</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">scopes</span><span class="params">(array $scopes)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> $builder = <span class="keyword">$this</span>;</div><div class="line"></div><div class="line"> <span class="keyword">foreach</span> ($scopes <span class="keyword">as</span> $scope => $parameters) {</div><div class="line"> <span class="keyword">if</span> (is_int($scope)) {</div><div class="line"> <span class="keyword">list</span>($scope, $parameters) = [$parameters, []];</div><div class="line"> }</div><div class="line"></div><div class="line"> $builder = $builder->callScope(</div><div class="line"> [<span class="keyword">$this</span>->model, <span class="string">'scope'</span>.ucfirst($scope)],</div><div class="line"> (<span class="keyword">array</span>) $parameters</div><div class="line"> );</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">return</span> $builder;</div><div class="line">}</div></pre></td></tr></table></figure>
<h2 id="fill-批量赋值"><a href="#fill-批量赋值" class="headerlink" title="fill 批量赋值"></a>fill 批量赋值</h2><p><code>Eloquent Model</code> 默认只能一个一个的设置数据库对象的属性，这是为了保护数据库。但是有的时候，字段过多会造成代码很繁琐。因此，<code>laravel</code> 提供属性批量赋值的功能，<code>fill</code> 函数，相关的官方文档：<a href="https://d.laravel-china.org/docs/5.5/eloquent#mass-assignment" target="_blank" rel="external">批量赋值</a></p>
<h3 id="fill-函数"><a href="#fill-函数" class="headerlink" title="fill 函数"></a>fill 函数</h3><figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div><div class="line">15</div><div class="line">16</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">fill</span><span class="params">(array $attributes)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> $totallyGuarded = <span class="keyword">$this</span>->totallyGuarded();</div><div class="line"></div><div class="line"> <span class="keyword">foreach</span> (<span class="keyword">$this</span>->fillableFromArray($attributes) <span class="keyword">as</span> $key => $value) {</div><div class="line"> $key = <span class="keyword">$this</span>->removeTableFromKey($key);</div><div class="line"></div><div class="line"> <span class="keyword">if</span> (<span class="keyword">$this</span>->isFillable($key)) {</div><div class="line"> <span class="keyword">$this</span>->setAttribute($key, $value);</div><div class="line"> } <span class="keyword">elseif</span> ($totallyGuarded) {</div><div class="line"> <span class="keyword">throw</span> <span class="keyword">new</span> MassAssignmentException($key);</div><div class="line"> }</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>;</div><div class="line">}</div></pre></td></tr></table></figure>
<p><code>fill</code> 函数会从参数 <code>attributes</code> 中选取可以批量赋值的属性。所谓的可以批量赋值的属性，是指被 <code>fillable</code> 或 <code>guarded</code> 成员变量设置的参数。被放入 <code>fillable</code> 的属性允许批量赋值的属性，被放入 <code>guarded</code> 的属性禁止批量赋值。</p>
<p>获取可批量赋值的属性：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div><div class="line">15</div><div class="line">16</div><div class="line">17</div><div class="line">18</div><div class="line">19</div><div class="line">20</div><div class="line">21</div><div class="line">22</div><div class="line">23</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">protected</span> <span class="function"><span class="keyword">function</span> <span class="title">fillableFromArray</span><span class="params">(array $attributes)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">if</span> (count(<span class="keyword">$this</span>->getFillable()) > <span class="number">0</span> && ! <span class="keyword">static</span>::$unguarded) {</div><div class="line"> <span class="keyword">return</span> array_intersect_key($attributes, array_flip(<span class="keyword">$this</span>->getFillable()));</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">return</span> $attributes;</div><div class="line">}</div><div class="line"></div><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">getFillable</span><span class="params">()</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->fillable;</div><div class="line">}</div><div class="line">``` </div><div class="line">可以看到，若想要实现批量赋值，需要将属性设置在 `fillable` 成员数组中。</div><div class="line"></div><div class="line">在 `laravel` 中，有一种数据库对象关系是 `morph`，也就是 `多态` 关系，这种关系也会调用 `fill` 函数，这个时候传入的参数 `attributes` 会带有数据库前缀。接下来，就要调用 `removeTableFromKey` 函数来去除数据库前缀：</div><div class="line"></div><div class="line">```php</div><div class="line"><span class="keyword">protected</span> <span class="function"><span class="keyword">function</span> <span class="title">removeTableFromKey</span><span class="params">($key)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">return</span> Str::contains($key, <span class="string">'.'</span>) ? last(explode(<span class="string">'.'</span>, $key)) : $key;</div><div class="line">}</div></pre></td></tr></table></figure>
<p>下一步，还要进一步验证属性的 <code>fillable</code>：</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div><div class="line">15</div><div class="line">16</div><div class="line">17</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">isFillable</span><span class="params">($key)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">if</span> (<span class="keyword">static</span>::$unguarded) {</div><div class="line"> <span class="keyword">return</span> <span class="keyword">true</span>;</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">if</span> (in_array($key, <span class="keyword">$this</span>->getFillable())) {</div><div class="line"> <span class="keyword">return</span> <span class="keyword">true</span>;</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">if</span> (<span class="keyword">$this</span>->isGuarded($key)) {</div><div class="line"> <span class="keyword">return</span> <span class="keyword">false</span>;</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">return</span> <span class="keyword">empty</span>(<span class="keyword">$this</span>->getFillable()) &&</div><div class="line"> ! Str::startsWith($key, <span class="string">'_'</span>);</div><div class="line">}</div></pre></td></tr></table></figure>
<p>如果当前 <code>unguarded</code> 开启，也就是不会保护任何属性，那么直接返回 <code>true</code>。如果当前属性在 <code>fillable</code> 中，也会返回 <code>true</code>。如果当前属性在 <code>guarded</code> 中，返回 <code>false</code>。最后，如果 <code>fillable</code> 是空数组，也会返回 <code>true</code>。</p>
<h3 id="forceFill"><a href="#forceFill" class="headerlink" title="forceFill"></a>forceFill</h3><p>如果不想受 <code>fillable</code> 或者 <code>guarded</code> 等的影响，还可以使用 <code>forceFill</code> 强制来批量赋值。</p>
<figure class="highlight php"><table><tr><td class="gutter"><pre><div class="line">1</div><div class="line">2</div><div class="line">3</div><div class="line">4</div><div class="line">5</div><div class="line">6</div><div class="line">7</div><div class="line">8</div><div class="line">9</div><div class="line">10</div><div class="line">11</div><div class="line">12</div><div class="line">13</div><div class="line">14</div><div class="line">15</div><div class="line">16</div><div class="line">17</div><div class="line">18</div><div class="line">19</div><div class="line">20</div><div class="line">21</div></pre></td><td class="code"><pre><div class="line"><span class="keyword">public</span> <span class="function"><span class="keyword">function</span> <span class="title">forceFill</span><span class="params">(array $attributes)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">return</span> <span class="keyword">static</span>::unguarded(<span class="function"><span class="keyword">function</span> <span class="params">()</span> <span class="title">use</span> <span class="params">($attributes)</span> </span>{</div><div class="line"> <span class="keyword">return</span> <span class="keyword">$this</span>->fill($attributes);</div><div class="line"> });</div><div class="line">}</div><div class="line"></div><div class="line"><span class="keyword">public</span> <span class="keyword">static</span> <span class="function"><span class="keyword">function</span> <span class="title">unguarded</span><span class="params">(callable $callback)</span></span></div><div class="line"><span class="function"></span>{</div><div class="line"> <span class="keyword">if</span> (<span class="keyword">static</span>::$unguarded) {</div><div class="line"> <span class="keyword">return</span> $callback();</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="keyword">static</span>::unguard();</div><div class="line"></div><div class="line"> <span class="keyword">try</span> {</div><div class="line"> <span class="keyword">return</span> $callback();</div><div class="line"> } <span class="keyword">finally</span> {</div><div class="line"> <span class="keyword">static</span>::reguard();</div><div class="line"> }</div><div class="line">}</div></pre></td></tr></table></figure>
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