完整性約束違規在Laravel播種數據庫時5

Question

我想我的種子數據庫Laravel 5.遷移成功，但是試圖種子時，我得到一個錯誤：

[PDOException] 
SQLSTATE[23000]: Integrity constraint violation: 1452 Cannot add or update a child row: a foreign key constraint fails (`ict302`.`psas`, CONSTRAINT `psas_psa_user_ 
id_foreign` FOREIGN KEY (`psa_user_id`) REFERENCES `users` (`id`)) 

下面是我的遷移：

用戶表：

class CreateUsersTable extends Migration 
{ 
    /** 
    * Run the migrations. 
    * 
    * @return void 
    */ 
    public function up() 
{ 
    Schema::create('users', function (Blueprint $table) { 
     $table->increments('id'); 
     $table->string('name'); 
     $table->string('email')->unique(); 
     $table->string('password')->nullable(); 
     $table->rememberToken(); 
     $table->timestamps(); 
    }); 
} 

/** 
* Reverse the migrations. 
* 
* @return void 
*/ 
public function down() 
{ 
    DB::statement('SET FOREIGN_KEY_CHECKS=0;'); 
    Schema::dropIfExists('users'); 
    DB::statement('SET FOREIGN_KEY_CHECKS=1;'); 
} 

PSA表：

public function up() 
    { 
     Schema::create('psas', function (Blueprint $table) { 
      $table->increments('psa_id'); 
      $table->timestamps(); 
      $table->string('psa_email',50); 
      $table->unique('psa_email'); 
      $table->string('psa_name', 30); 
      $table->integer('psa_user_id')->unsigned()->onDelete('cascade'); 
     }); 

     Schema::table('psas', function (Blueprint $table) 
     { 
      $table->foreign('psa_user_id')->references('id')->on('users'); 
     }); 
    } 

    /** 
    * Reverse the migrations. 
    * 
    * @return void 
    */ 
    public function down() 
    { 
     DB::statement('SET FOREIGN_KEY_CHECKS=0;'); 
     Schema::dropIfExists('psas'); 
     DB::statement('SET FOREIGN_KEY_CHECKS=1;'); 
    } 

數據庫播種機類：

public function run() 
    { 
     //Model::unguard(); 
     DB::statement('SET FOREIGN_KEY_CHECKS=0;'); 
     $this->call(AccessTableSeeder::class); 
     $this->call(HistoryTypeTableSeeder::class); 

     $this->call(UserTableSeeder::class); 
     $this->call(PsaTableSeeder::class); 
     DB::statement('SET FOREIGN_KEY_CHECKS=1;'); 
     //Model::reguard(); 
    } 

什麼我做錯了，我該如何解決？

Answer 1

@Gautam納特

您可以嘗試使用下面的概念。例如：如果你想USER_ID在「公益廣告」表的外鍵，然後裏面了函數如下定義。

$table->integer('user_id')->unsigned()->nullable(); 

$table->foreign('user_id')->references('id')->on('users')->onDelete('cascade')->onUpdate('cascade');