feat: add opt WithSQLNullType

config.go

@@ -115,6 +115,30 @@ func (cfg *Config) WithImportPkgPath(paths ...string) {
 	cfg.importPkgPaths = append(cfg.importPkgPaths, paths...)
 }
 
+// WithSQLNullType
+/**
+ * This function configures the types of fields to use their SQL nullable counterparts.
+ *
+ * @param {boolean} all - If true, all basic types of fields will be replaced with their `sql.NullXXX` types.
+ *                        If false, only fields that are allowed to be null will be replaced with `sql.NullXXX` types.
+ *
+ * Examples:
+ *
+ * When `all` is true:
+ * - `int64` will be replaced with `sql.NullInt64`
+ * - `string` will be replaced with `sql.NullString`
+ *
+ * When `all` is false:
+ * - Only fields that can be null (e.g., `*string` or `*int`) will be replaced with `sql.NullXXX` types.
+ *
+ * Note:
+ * Ensure that proper error handling is implemented when converting
+ * fields to their `sql.NullXXX` types to avoid runtime issues.
+ */
+func (cfg *Config) WithSQLNullType(all bool) {
+	cfg.WithOpts(WithSQLNullType(all))
+}
+
 // Revise format path and db
 func (cfg *Config) Revise() (err error) {
 	if strings.TrimSpace(cfg.ModelPkgPath) == "" {

field_options.go

@@ -25,6 +25,59 @@ var (
 			return opt(f)
 		}
 	}
+	// WithSQLNullType
+	/**
+	 * This function configures the types of fields to use their SQL nullable counterparts.
+	 *
+	 * @param {boolean} all - If true, all basic types of fields will be replaced with their `sql.NullXXX` types.
+	 *                        If false, only fields that are allowed to be null will be replaced with `sql.NullXXX` types.
+	 *
+	 * Examples:
+	 *
+	 * When `all` is true:
+	 * - `int64` will be replaced with `sql.NullInt64`
+	 * - `string` will be replaced with `sql.NullString`
+	 *
+	 * When `all` is false:
+	 * - Only fields that can be null (e.g., `*string` or `*int`) will be replaced with `sql.NullXXX` types.
+	 *
+	 * Note:
+	 * Ensure that proper error handling is implemented when converting
+	 * fields to their `sql.NullXXX` types to avoid runtime issues.
+	 */
+	WithSQLNullType = func(all bool) model.ModifyFieldOpt {
+		return func(f *model.Field) *model.Field {
+			ft := f.Type
+			nullable := false
+			if strings.HasPrefix(ft, "*") {
+				nullable = true
+				ft = ft[1:]
+			}
+			if !all && !nullable {
+				return f
+			}
+
+			switch ft {
+			case "string":
+				f.Type = "sql.NullString"
+			case "int", "int64", "uint", "uint32", "uint64":
+				f.Type = "sql.NullInt64"
+			case "uint16", "int32":
+				f.Type = "sql.NullInt32"
+			case "int8", "uint8", "int16":
+				f.Type = "sql.NullInt16"
+			case "byte":
+				f.Type = "sql.NullByte"
+			case "float64", "float32":
+				f.Type = "sql.NullFloat64"
+			case "bool":
+				f.Type = "sql.NullBool"
+			case "time.Time":
+				f.Type = "sql.NullTime"
+			}
+			return f
+		}
+	}
 
 	// FieldNew add new field (any type your want)
 	FieldNew = func(fieldName, fieldType string, fieldTag field.Tag) model.CreateFieldOpt {