Address issue #49

README.md

@@ -205,39 +205,23 @@ $migration->getDbDriver();
 
 To use it, please visit: <https://github.com/byjg/anydataset-db>
 
-## Tips on writing SQL migrations for Postgres
+### Avoiding Partial Migration
 
-### Rely on explicit transactions
+A partial migration is when the migration script is interrupted in the middle of the process due to an error or a manual interruption.
 
-```sql
--- DO
-BEGIN;
+The migration table will be with the status `partial up` or `partial down` and it needs to be fixed manually before be able to migrate again. 
 
-ALTER TABLE 1;
-UPDATE 1;
-UPDATE 2;
-UPDATE 3;
-ALTER TABLE 2;
+To avoid this situation you can specify the migration will be run in a transactional context. 
+If the migration script fails, the transaction will be rolled back and the migration table will be marked as `complete` and 
+the version will be the immediately previous version before the script that causes the error.
 
-COMMIT;
+To enable this feature you need to call the method `withTransactionEnabled` passing `true` as parameter:
 
-
--- DON'T
-ALTER TABLE 1;
-UPDATE 1;
-UPDATE 2;
-UPDATE 3;
-ALTER TABLE 2;
+```php
+<?php
+$migration->withTransactionEnabled(true);
 ```
-
-It is generally desirable to wrap migration scripts inside a `BEGIN; ... COMMIT;` block.
-This way, if _any_ of the inner statements fail, _none_ of them are committed and the
-database does not end up in an inconsistent state.
-
-Mind that in case of a failure `byjg/migration` will always mark the migration as `partial`
-and warn you when you attempt to run it again. The difference is that with explicit
-transactions you know that the database cannot be in an inconsistent state after an
-unexpected failure.
+## Tips on writing SQL migrations for Postgres
 
 ### On creating triggers and SQL functions
 

src/Migration.php

@@ -50,6 +50,8 @@ class Migration
      */
     private $migrationTable;
 
+    private $transaction = false;
+
     /**
      * Migration constructor.
      *
@@ -69,10 +71,14 @@ public function __construct(UriInterface $uri, $folder, $requiredBase = true, $m
         $this->migrationTable = $migrationTable;
     }
 
+    public function withTransactionEnabled($enabled = true)
+    {
+        $this->transaction = $enabled;
+        return $this;
+    }
+
     /**
-     * @param $scheme
-     * @param $className
-     * @return $this
+     * @param $class
      */
     public static function registerDatabase($class)
     {
@@ -327,9 +333,22 @@ protected function migrate($upVersion, $increment, $force)
                 call_user_func_array($this->callableProgress, ['migrate', $currentVersion, $fileInfo]);
             }
 
-            $this->getDbCommand()->setVersion($currentVersion, Migration::VERSION_STATUS_PARTIAL . ' ' . ($increment>0 ? 'up' : 'down'));
-            $this->getDbCommand()->executeSql($fileInfo["content"]);
-            $this->getDbCommand()->setVersion($currentVersion, Migration::VERSION_STATUS_COMPLETE);
+            try {
+                if ($this->transaction) {
+                    $this->getDbDriver()->beginTransaction();
+                }
+                $this->getDbCommand()->setVersion($currentVersion, Migration::VERSION_STATUS_PARTIAL . ' ' . ($increment>0 ? 'up' : 'down'));
+                $this->getDbCommand()->executeSql($fileInfo["content"]);
+                $this->getDbCommand()->setVersion($currentVersion, Migration::VERSION_STATUS_COMPLETE);
+                if ($this->transaction) {
+                    $this->getDbDriver()->commitTransaction();
+                }
+            } catch (\Exception $e) {
+                if ($this->transaction) {
+                    $this->getDbDriver()->rollbackTransaction();
+                }
+                throw $e;
+            }
             $currentVersion = $currentVersion + $increment;
         }
     }

tests/MigrationTest.php

@@ -1,6 +1,7 @@
 <?php
 namespace Test;
 
+use ByJG\DbMigration\Database\SqliteDatabase;
 use ByJG\DbMigration\Exception\InvalidMigrationFile;
 use ByJG\DbMigration\Migration;
 use ByJG\Util\Uri;
@@ -113,8 +114,8 @@ public function testGetFileContent_1()
                 "file" => __DIR__ . '/dirstructure/migrations/up/00001.sql',
                 "description" => "this is a test",
                 "exists" => true,
-                "checksum" => "b937afa57e363c9244fa30844dd11d312694f697",
-                "content" => "-- @description: this is a test\n\nselect * from mysql.users;\n",
+                "checksum" => "55249baf6b70c1d2e9c5362de133b2371d0dc989",
+                "content" => "-- @description: this is a test\n",
             ],
             $this->object->getFileContent(__DIR__ . '/dirstructure/migrations/up/00001.sql')
         );
@@ -127,8 +128,8 @@ public function testGetFileContent_2()
                 "file" => __DIR__ . '/dirstructure/migrations/up/00002.sql',
                 "description" => "another test",
                 "exists" => true,
-                "checksum" => "fd8ab8176291c2dcbf0d91564405e0f98f0cd77e",
-                "content" => "--   @description:  another test\n\nselect * from dual;",
+                "checksum" => "f20c73a5eb4d29e2f8edae4409a2ccc2b02c6f67",
+                "content" => "--   @description:  another test\n",
             ],
             $this->object->getFileContent(__DIR__ . '/dirstructure/migrations/up/00002.sql')
         );
@@ -141,10 +142,41 @@ public function testGetFileContent_3()
                 "file" => __DIR__ . '/dirstructure/migrations/up/00003.sql',
                 "description" => "no description provided. Pro tip: use `-- @description:` to define one.",
                 "exists" => true,
-                "checksum" => "73faaa68e2f60c11e75a9ccc18528e0ffa15127a",
-                "content" => "select something from sometable;",
+                "checksum" => "da39a3ee5e6b4b0d3255bfef95601890afd80709",
+                "content" => "",
             ],
             $this->object->getFileContent(__DIR__ . '/dirstructure/migrations/up/00003.sql')
         );
     }
+
+    public function testReset()
+    {
+        $this->expectException(\PDOException::class);
+        Migration::registerDatabase(SqliteDatabase::class);
+        $this->object = new Migration(new Uri('sqlite:///tmp/test.db'), __DIR__ . '/dirstructure2');
+        $this->object->reset();
+    }
+
+    public function testResetWithoutTransactionCheck()
+    {
+        try {
+            Migration::registerDatabase(SqliteDatabase::class);
+            $this->object = new Migration(new Uri('sqlite:///tmp/test.db'), __DIR__ . '/dirstructure2');
+            $this->object->reset();
+        } catch (\PDOException $ex) {
+            $this->assertEquals(["version" => '2', "status" => "partial up"], $this->object->getCurrentVersion());
+        }
+    }
+
+    public function testResetWithTransactionCheck()
+    {
+        try {
+            Migration::registerDatabase(SqliteDatabase::class);
+            $this->object = new Migration(new Uri('sqlite:///tmp/test.db'), __DIR__ . '/dirstructure2');
+            $this->object->withTransactionEnabled();
+            $this->object->reset();
+        } catch (\PDOException $ex) {
+            $this->assertEquals(["version" => '1', "status" => "complete"], $this->object->getCurrentVersion());
+        }
+    }
 }

tests/dirstructure/migrations/up/00001.sql

@@ -1,3 +1 @@
 -- @description: this is a test
-
-select * from mysql.users;

tests/dirstructure/migrations/up/00002.sql

@@ -1,3 +1 @@
 --   @description:  another test
-
-select * from dual;

tests/dirstructure/migrations/up/00003.sql

@@ -1 +0,0 @@
-select something from sometable;

tests/dirstructure2/migrations/up/00002.sql

@@ -0,0 +1 @@
+error