Laravel放弃迁移中的外键 [英] Laravel drop foreign Key in Migration

问题描述

我想创建一个将删除表的迁移.我这样创建了迁移:

I want to create a Migration which shall drop a table. I created the Migration like this:

Schema::table('devices', function (Blueprint $table) {
    $table->increments('id');
    $table->unsignedInteger('client_id')->nullable();
    $table->foreign('client_id')->references('id')->on('clients')->onDelete('cascade');
});

现在我尝试像这样删除它:

And now I try to drop it like this:

    Schema::table('devices', function (Blueprint $table) {
        $table->dropForeign('devices_client_id_foreign');
        $table->drop('devices');
    });

但是我收到以下错误消息:

But I get following error:

In Connection.php line 664:

  SQLSTATE[42000]: Syntax error or access violation: 1091 Can't DROP 'devices_client_id_foreign'; check that column/key exists (SQL:

更改表devices删除外键devices_client_id_foreign)

In PDOStatement.php line 144:

  SQLSTATE[42000]: Syntax error or access violation: 1091 Can't DROP 'devices_client_id_foreign'; check that column/key exists


In PDOStatement.php line 142:

  SQLSTATE[42000]: Syntax error or access violation: 1091 Can't DROP 'devices_client_id_foreign'; check that column/key exists

推荐答案

您只需要在删除表之前禁用外键检查，然后按如下所示再次启用外键检查:

You just need to disable foreign key checks before you drop the table then enable them again after like this:

DB::statement('SET FOREIGN_KEY_CHECKS=0;');
Schema::dropIfExists('devices');
DB::statement('SET FOREIGN_KEY_CHECKS=1;');

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