php - 我不能做外键，约束错误

Question

我有一个通信错误，我无法解决它，已知为 [Illuminate\Database\QueryException] SQLSTATE[42000]这是完整的错误:

[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

他是我想做外键的表:

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');
        });
    }

鼻涕虫

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');
    }

我想做的是添加到 files table *slug column*来自 slugs table .

Answer 1

我猜 string 数据类型不能是 unsigned()，这就是您收到错误的原因。

在两个迁移中使用它:

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