Laravel迁移在非主要迁移时使用自动增量

Question

我正在尝试创建一个包含 Laravel 迁移的表，但我遇到了一些麻烦。我只需要创建一个带有主对("user_id"和"media_id"(的表，即"inc"自动增量。我可以在 MySQL 中做到这一点，但我无法使用 Laravel 迁移来做到这一点，因为 increments(( 也将字段设置为主要字段。我得到的错误

 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

到目前为止，我就完成了

 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

我找到了问题的解决方案，即在创建架构后定义该列 inc(自动递增(。

它应该是怎样的

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');
            
        // });
    }

切马