在关系中指定透视表。默认Laravel假设 admin_role Admin Role

protected $table = 'pjt_roles';

public function Admin(){ // should be admins() for better readability
    return $this->belongsToMany(Admin::class, 'pjt_role_admin');
}

public function Role(){ // should be roles() for better readability
    return $this->belongsToMany(Role::class, 'pjt_role_admin');
}

关系的连接表,雄辩的将连接两个相关模型 公约。您可以通过将第二个参数传递给

获取数据

$admin = Admin::find(1);
$roles = $admin->Role; // should change to roles() in relationship for better readability

$admin->Role()->attach($roleId);

细节 https://laravel.com/docs/5.4/eloquent-relationships#many-to-many