Laravel看起来像一个非常好的
PHP框架,捆绑了一个很好的ORM(Eloquent).然而,laravel文档是缺乏的东西.文档中只包含基本内容.
无论如何,当涉及到超过2个模型的Eloquent和模型关系时,我遇到了问题.
例如,我有以下场景.
我有四个数据库表,即：users,locations,users_locations,packages.
模型/表格之间的关系如下：
用户可以属于许多位置,反之亦然.
一个位置可以有很多包.
我相应的模型关系如下：
//User Model:
public function locations(){
return $this->belongsToMany('Location','users_locations','user_id','location_id');
}
//Location Model:
public function users(){
return $this->belongsToMany('User','location_id','user_id');
}
public function packages(){
return $this->hasMany('Package','location_id');
}
//Package Model:
public function location(){
return $this->belongsTo('Location','location_id');
}
我想做什么？：我想让所有的软件包都属于用户.用户属于位置,而包也属于位置.因此,从属于用户的所有位置,我想要检索属于用户的那些位置的包.
我还希望对结果集进行分页.
我尝试过以下方法：
//get the logged in user ID
$userId = Auth::user()->id
//first get all the locations of the user
$locations= User::with('locations')->find($userId)->locations;
//declare an empty array to store the packages
$packages = array();
//now loop through the locations
foreach($locations as $location){
//since each location can have many packages,we also have to loop through the packages
foreach($location->packages as $package){
//store the plan in the array
$packages[] = $package;
}
}
//ok now we got the list of packages
return $packages;
问题是,由于上述原因,我无法对包进行分页.有没有人知道如何正确地使用Eloquent以有效的方式做到这一点？或者它是不可能的？
//get the logged in user ID
$userId = Auth::user()->id
//first get all the locations of the user
$locations= User::with('locations')->find($userId)->locations;
/* perhaps you can alternatively use lists() function to get the ids
something like: $loc_ids = DB::table('locations')->where('user_id',$userId)->lists('id'); */
$loc_ids = array();
foreach($locations as $location)
{
$loc_ids[] = $location->id;
}
$packages = Package::whereIn('location_id',$loc_ids)->skip($offset)->take($page_size)->get();
return $packages;
