dousao6260 2018-05-20 19:10 采纳率: 0%
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无法使用Mysql在Laravel中创建外键

I have a project and i have call these 2 commands at the first in my command prompt:

php artisan make:model Music -m
php artisan make:model Artist -m

Then i create a foreign key in music migration file like this :

public function up()
{
    Schema::create('musics', function (Blueprint $table) {
        $table->increments('id');
        $table->integer('artist_id')->unsigned();
        $table->timestamps();
        $table->foreign('artist_id')->references('id')->on('artists');
    });
}

Now when i run migrate command like :

php artisan migrate

But i have a this error :

       Illuminate\Database\QueryException  : SQLSTATE[HY000]: General error: 1215 Cannot add foreign key constraint (SQL: alter table `musics` add constraint `musics_artist_id_foreign` foreign key (`artist_id`) references `artists` (`id`) on delete cascade)

  at D:\sites\laravel\MrMusic\vendor\laravel\framework\src\Illuminate\Database\Connection.php:664
    660|         // If an exception occurs when attempting to run a query, we'll format the error
    661|         // message to include the bindings with SQL, which will make this exception a
    662|         // lot more helpful to the developer instead of just the database's errors.
    663|         catch (Exception $e) {
  > 664|             throw new QueryException(
    665|                 $query, $this->prepareBindings($bindings), $e
    666|             );
    667|         }
    668|

  Exception trace:

  1   PDOException::("SQLSTATE[HY000]: General error: 1215 Cannot add foreign key constraint")
      D:\sites\laravel\MrMusic\vendor\laravel\framework\src\Illuminate\Database\Connection.php:458

  2   PDOStatement::execute()
      D:\sites\laravel\MrMusic\vendor\laravel\framework\src\Illuminate\Database\Connection.php:458

  Please use the argument -v to see more details.

Note : i will test a few ways like set index to both of fields,...

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4条回答 默认 最新

  • doulu6929 2018-05-31 15:11
    关注

    I dont't have any mistake in create migrations file.

    My mistake is in create function for realation in Artist model:

    In my Artist.php i used :

    public function music(){ ... }
    

    Now i forget to set like this :

    public function musics(){ ... }
    
    本回答被题主选为最佳回答 , 对您是否有帮助呢?
    评论
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