Laravel 5.4 中的 3 个模型多对多同步

Question

我有 3 个具有多对多关系的模型：

模块

public function permissionTypes()
{
    return $this->belongsToMany(PermissionType::class, 'permissions')->withPivot('role_id');
}

public function roles()
{
    return $this->belongsToMany(Role::class, 'permissions')->withPivot('permission_type_id');
}

角色

public function permissionTypes()
{
    return $this->belongsToMany(PermissionType::class, 'permissions')->withPivot('module_id');
}

public function modules()
{
    return $this->belongsToMany(Module::class, 'permissions')->withPivot('permission_type_id');
}

权限类型

public function roles() 
{
    return $this->belongsToMany(Role::class, 'permissions')->withPivot('module_id');
}

public function modules()
{
    return $this->belongsToMany(Module::class, 'permissions')->withPivot('role_id');
}

表格说明：

模块

id
title
status

角色

id
title

permission_types

id
title

数据透视表权限

id
role_id
module_id
permission_type_id

我的同步看起来像：

//array of ids from request to synchronization 
$permissions = $request['permissions'];

//role by id from request
$role = Role::findOrFail((int)$roleId);

//module by id from request
$module = Module::findOrFail((int)$moduleId);

//synchronization
$pivotData = array_fill(0, count($permissions), ['role_id' => $role->id]);
$syncData  = array_combine($permissions, $pivotData);
$module->permissionTypes()->sync($syncData);

尝试同步时出错

Connection.php 第 647 行中的 QueryException： SQLSTATE[42000]: 语法错误或访问冲突: 1066 Not unique table/alias: 'permissions' (SQL: select permissions.*, permissions.role_id as pivot_role_id, permissions.permission_id作为pivot_permission_id 从permissions 内部连接permissions 在permissions.id = permissions.permission_id 其中permissions.role_id = 1)

谢谢

Answer 1

恕我直言，您正在尝试设计 Laravel 中不存在的三重多对多。解决方案通常是为数据透视表（在您的情况下为 permissions）提供一个模型（Permission 在下面的代码中）用于定义 hasManyThrough 关系。

如果我理解你的表结构，我会设计以下关系：

模块

public function permissions()
{
    return $this->hasMany(Permission::class);
}
public function roles()
{
    return $this->hasManyThrough(Role::class, Permission::class);
}
public function permissionTypes()
{
    return $this->hasManyThrough(PermissionType::class, Permission::class);
}

角色

public function permissions()
{
    return $this->hasMany(Permission::class);
}
public function permissionTypes()
{
   return $this->hasManyThrough(PermissionType::class, Permission::class);
}   
public function modules()
{
    return $this->hasManyThrough(Module::class, Permission::class);
}

权限类型

public function permissions()
{
    return $this->hasMany(Permission::class);
}
public function modules()
{
    return $this->hasManyThrough(Module::class, Permission::class);
}
public function roles()
{
   return $this->hasManyThrough(Role::class, Permission::class);
}

权限

public function permissionType()
{
    return $this->belongsTo(PermissionType::class);
}
public function role()
{
    return $this->belongsTo(Role::class);
}
public function module()
{
    return $this->belongsTo(Module::class);
}

告诉我它是否适合你。