在Laravel迁移中重命名现有列的错误

Question

我添加了一个新的迁移来重命名旧列。 对于我来说，这段代码中的一切似乎都是正确的：

public function up()
{
   Schema::table('reports', function (Blueprint $table) {
        $table->renameColumn('reporter_id', 'created_by');
    });
}

/**
 * Reverse the migrations.
 *
 * @return void
 */
public function down()
{
    Schema::table('reports', function (Blueprint $table) {
        $table->renameColumn('created_by', 'reporter_id');
    });
}

但后来我遇到了一个错误：

In Connection.php line 664: SQLSTATE[0A000]: Feature not supported: 1846 ALGORITHM=COPY is not supported. Reason: Columns participating in a foreign key are renamed. Try ALGORITHM=INPLACE. (SQL: ALTER TABLE reports CHANGE reporter_id created_b    y INT NOT NULL)                                                                                                                                                                                                          
In PDOStatement.php line 140: SQLSTATE[0A000]: Feature not supported: 1846 ALGORITHM=COPY is not supported. Reason: Columns participating in a foreign key are renamed. Try ALGORITHM=INPLACE.
In PDOStatement.php line 138: SQLSTATE[0A000]: Feature not supported: 1846 ALGORITHM=COPY is not supported. Reason: Columns participating in a foreign key are renamed. Try ALGORITHM=INPLACE. `

你能帮我解决这个问题吗？

Answer 1

首先在up方法上放下koreign key 。

public function up()
{
  Schema::table('reports', function (Blueprint $table) {
     $table->dropForeign('reports_reporter_id_foreign');
     $table->renameColumn('reporter_id', 'created_by');
  });
}

然后在down方法上再次添加foreign key 。

public function down()
{
    Schema::table('reports', function (Blueprint $table) {
        $table->renameColumn('created_by', 'reporter_id');
        $table->foreign('reporter_id')->references('id')->on('your_related_table')->onDelete('cascade');
    });
}

Answer 2

我也遇到过这种情况 - 这没有任何意义，因为当我使用我的标准SQL客户端重命名相同的字段时...它可以工作。 但它只是不能用作迁移脚本。 因此，我最终在DB::statement运行RENAME ，这对我有用：

     /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {

        DB::statement("ALTER TABLE `mydb`.`mytable`   
          CHANGE `currentfieldname` `newfieldname` 
          INT(10) UNSIGNED NOT NULL;");

    }