用複合鍵錯誤地形成外鍵約束

Question

我有一個表「劇院」。其中（theater_name，area_name，station）是組合鍵。在表格「立方體列表」中，我有列表（thtr_name，area，stn），它們將被引用（劇院名稱，area_name，電臺）爲表格「劇院」。

這裏的問題是表中「劇院」中的列（劇院名，區域名，電臺）的組合是唯一的，因爲它是一個組合鍵。但是，每一列分別不是唯一的。

那麼我該如何從表格「cubelists」中引用這些列呢？

Schema::create('theaters', function (Blueprint $table) { 

     $table->string('theater_name'); 
     $table->string('area_name'); 
     $table->string('station'); 
     $table->primary(array('theater_name','area_name','station')); 
     $table->text('address'); 
     $table->bigInteger('phno'); 
     $table->string('contact_person'); 

    }); 



    public function up() 
    { 
    // 
    Schema::create('cubelists', function (Blueprint $table) { 
     $table->string('mvie_name'); 
     $table->foreign('mvie_name')->references('movie_name')->on('movies'); 
     $table->string('thtr_name'); 

     $table->string('area'); 

     $table->string('stn'); 

     $table->foreign(array('thtr_name','area','stn'))- 
     >references(array('theater_name','area_name','station'))- 
     >on('theaters'); 
     $table->primary(array('mvie_name','thtr_name','area','stn')); 
     $table->string('type'); 
     $table->string('subtype'); 
     $table->date('validity'); 
     $table->string('show'); 

    }); 

} 

如果我給上面的代碼中，我得到一個錯誤的

Migration table created successfully. 


    [Illuminate\Database\QueryException] 
    SQLSTATE[HY000]: General error: 1005 Can't create table `boras_cachii`.`#sql-a10_ 
    112` (errno: 150 "Foreign key constraint is incorrectly formed") (SQL: alter tabl 
    e `agreements` add constraint agreements_area_name_foreign foreign key (`area_nam 
    e`) references `cubelists` (`area`)) 



    [PDOException] 
    SQLSTATE[HY000]: General error: 1005 Can't create table `boras_cachii`.`#sql-a10_ 
    112` (errno: 150 "Foreign key constraint is incorrectly formed") 

Answer 1

您必須先創建表，然後外鍵。

Schema::create('cubelists', function (Blueprint $table) { 
     $table->string('mvie_name'); 
     $table->string('area'); 
     $table->string('stn'); 
     $table->primary(array('mvie_name','thtr_name','area','stn')); 
     $table->string('type'); 
     $table->string('subtype'); 
     $table->date('validity'); 
     $table->string('show'); 

      $table->foreign(array('thtr_name','area','stn')) 
      ->references(array('theater_name','area_name','station')) 
      ->on('theaters'); 

      $table->foreign('mvie_name') 
      ->references('movie_name') 
      ->on('movies'); 


    }); 

而且theaters表必須先遷移自cubelists被引用它。並確保外鍵列和引用列的類型或長度相同。