如何獲得雄辯從中間表中的數據，硅石

Question

我創建數據庫表users，groups和group_user（MySQL的）。而group_user表（中間表）包含user_id和role_id。用戶和小組的關係很多。我想刪除groups表中的一個組。在刪除組之前，我想檢查是否有任何用戶屬於該組。 我試圖這樣做。

Group.php（型號）

public function users() 
    { 
     return $this->belongsToMany('\Modules\User\Models\User'); 
    } 

Service.php

public function deleteGroup($data) { 
    if (!isset($data['groupID'])) 
     return ['error' => 'Failed to delete group. Group id is required']; 

    $group = Group::find($data['groupID']); 
    if (!$group) 
     return ['error' => 'Failed to delete group. Group not found']; 

    // check any user belongs to group. 
    $result = $group->users()->pivot->user_id; 

    if(!$result){ 
     $group->delete(); 
     return ['success' => 'Successfully delete group.']; 
    } 
    return ['error' => 'Failed to delete group. Group not found']; 
} 

但是，這是行不通的。

Answer 1

我發現了。

service.php

public function deleteGroup($data) { 

    $group = Group::find($data['groupID']); 
    if (!$group){ 
     return [ 
      "msg" => "Failed to delete group. Group not found." 
     ]; 
    } 
    // find out any one belongs to the group.   
    $result = $group->users->first()->userID; 
    if ($result){ 
     return [ 
      "msg" => "Failed to delete group. Group has users." 
     ]; 
    } 

    $result = $group->delete($data['groupID']); 
    if(!$result){ 
     return [ 
      "msg" => "Failed to delete group." 
     ]; 
    } 

    return [ 
     "msg" => "Successfully deleted group." 
    ]; 
} 

這是我要做的事。如果有另一種方式，請告訴我。謝謝。