Question

我正在尝试使用Laravel迁移创建一个表，但我遇到了一些麻烦。我只需要创建一个带有主要对的表（'user_id'和'media_id'），'inc'是一个自动增量。我可以在MySQL中完成它，但是我无法通过Laravel Migrations来完成它，因为incrementments（）也将字段设置为主要字段。错误我得到

 SQLSTATE[42000]: Syntax error or access violation: 1075 Incorrect table definition; there can be only one auto column and it must be defined as a key

那是我到目前为止所做的那些

 public function up()
    {
        Schema::create('tagtables', function (Blueprint $table) {
            
            $table->integer('media_id');
            $table->integer('user_id');
            $table->boolean('approved')->default(false);
            $table->increments('inc')->unsigned();
            $table->timestamps();
            $table->dropPrimary('tagtables_inc_primary');
            $table->primary(array('user_id','media_id'));
                        
            // $table->foreign('media_id')->references('id')->on('media')->onUpdate('cascade')->onDelete('cascade');
            // $table->foreign('user_id')->references('id')->on('users')->onUpdate('cascade')->onDelete('cascade');
        });


        // Schema::table('tagtables', function (Blueprint $table) {
        //     //$table->increments('id');
        //     $table->primary(array('user_id','media_id'));
        //     $table->foreign('media_id')->references('id')->on('media')->onUpdate('cascade')->onDelete('cascade');
        //     $table->foreign('user_id')->references('id')->on('users')->onUpdate('cascade')->onDelete('cascade');
            
        // });
    }

Answer 1

我认为你需要这个：

public function up()
{
    Schema::create('tagtables', function (Blueprint $table) {
        $table->increments('inc');
        $table->integer('media_id')->unsigned();
        $table->integer('user_id')->unsigned();
        $table->boolean('approved')->default(false);
        $table->timestamps();

        $table->index(['user_id', 'media_id']);
        $table->foreign('media_id')->references('id')->on('media')->onUpdate('cascade')->onDelete('cascade');
        $table->foreign('user_id')->references('id')->on('users')->onUpdate('cascade')->onDelete('cascade');
    });
}

并将其放入模型中：

protected $primaryKey = 'inc';

Answer 2

我找到了解决问题的方法，即在创建模式后定义列inc（自动递增）。

应该如何

public function up()
    {
        Schema::create('tagtables', function (Blueprint $table) {
            
            $table->integer('media_id');
            $table->integer('user_id');
            $table->boolean('approved')->default(false);
           // $table->increments('inc');
            $table->timestamps();
          //  $table->dropPrimary( 'tagtables_inc_primary' );
            $table->primary(array('user_id','media_id'));
                        
            // $table->foreign('media_id')->references('id')->on('media')->onUpdate('cascade')->onDelete('cascade');
            // $table->foreign('user_id')->references('id')->on('users')->onUpdate('cascade')->onDelete('cascade');
        });

    DB::statement('ALTER Table tagtables add id INTEGER NOT NULL UNIQUE AUTO_INCREMENT;');
        // Schema::table('tagtables', function (Blueprint $table) {
        //     //$table->increments('id');
        //     $table->primary(array('user_id','media_id'));
        //     $table->foreign('media_id')->references('id')->on('media')->onUpdate('cascade')->onDelete('cascade');
        //     $table->foreign('user_id')->references('id')->on('users')->onUpdate('cascade')->onDelete('cascade');
            
        // });
    }

chema

当laravel迁移不是主要时，它会使用自动增量

2 个答案: