我不能做一个外键约束错误

Question

我有一个commum错误，我不能去了吧，知道作为[Illuminate\Database\QueryException] SQLSTATE[42000]这里是完整的错误：

[Illuminate\Database\QueryException] SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'unsigned null' at line 1 (SQL: alter table files add slug varchar(255) unsigned null)

分离的错误：

[PDOException] SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'unsigned null' at line 1

他是我想要做的外键的表：

文件

public function up() 
    { 
     Schema::create('files', function($table) 
     { 
      $table->engine = 'InnoDB'; 
      $table->increments('id')->unsigned(); 
      $table->string('name')->nullable(); 
      $table->boolean('enable_sch')->nullable(); 
      $table->datetime('schdate')->nullable(); 
      $table->string('flsize')->nullable(); 
      $table->timestamps(); 
     }); 
     Schema::table('files', function($table) 
     { 
      $table->string('slug')->unsigned()->nullable(); 
      $table->foreign('slug')->references('slug')->on('slugs'); 
     }); 
    } 

蛞蝓

public function up() 
    { 
     Schema::create('slugs', function($table) 
     { 
      $table->engine = 'InnoDB'; 
      $table->string('nameslug'); 
      $table->string('slug')->unsigned()->nullable(); 
      $table->timestamps(); 
     }); 
    } 
    public function down() 
    { 
     Schema::dropIfExists('slugs'); 
    } 

我试图做的是从slugs table添加到files table的*slug column*。

Answer 1

由于我使用OctoberCMS与Laravel，有relationships喜欢上了**models** file$hasMany和$belongsTo。  

如果有麻烦与此有关OctoberCMS，只是咨询this

Answer 2

我猜string数据类型不能是unsigned()，这就是为什么你得到一个错误。

两个迁移使用此：

$table->string('slug')->nullable();