Laravel 1215不能在我的laravel應用</p> <p>添加外鍵約束

Question

你好，我有麻煩我的數據庫遷移這是錯誤：

[Illuminate\Database\QueryException]           
    SQLSTATE[HY000]: General error: 1215 Cannot add foreign key constraint (SQL 
    : alter table `transactions` add constraint `transactions_user_sid_foreign` 
    foreign key (`user_sid`) references `users` (`sid`)) 

這是我的交易遷移：

public function up() 
    { 
     Schema::create('transactions', function (Blueprint $table) { 
      $table->increments('id'); 
      $table->unsignedInteger('user_sid')->index(); 
      $table->unsignedInteger('store_id')->index(); 
      $table->unsignedInteger('value'); 
      $table->timestamps(); 
      $table->softDeletes(); 
     }); 
    } 

這是用戶遷移：

public function up() 
    { 
     Schema::create('users', function (Blueprint $table) { 
      $table->increments('id'); 
      $table->string('name'); 
      $table->string('email')->unique(); 
      $table->string('password'); 
      $table->unsignedInteger('role_id')->index(); 
      $table->string('sid')->unique(); 
      $table->rememberToken(); 
      $table->timestamps(); 
      $table->softDeletes(); 
     }); 
    } 

最後我的外鍵：

Schema::table('transactions', function (Blueprint $table){ 
      $table->foreign('user_sid')->references('sid')->on('users'); 
      $table->foreign('store_id')->references('id')->on('stores'); 
     }); 

Answer 1

您不能在users表的外鍵添加到具有不同類型的列，所以只是改變它，例如：

$table->unsignedInteger('sid')->unique();