Laravel完全加入groupby並計數

Question

我正在努力讓拉拉維爾的主子女，伯爵（小孩）和所有主生，與groupby。下面是表格記錄和laravel代碼。

父表

+-------------+------------+ 
    | Id   | Name  | 
    +-------------+------------+ 
    | 1   | a   | 
    +-------------+------------+  
    | 2   | b   | 
    +-------------+------------+ 
    | 3   | c   | 
    +-------------+------------+ 

子表

+-------------+------------+ 
    | parent_Id | Code  | 
    +-------------+------------+ 
    | 1   | d1   | 
    +-------------+------------+ 
    | 1   | d1   | 
    +-------------+------------+  
    | 1   | d1   | 
    +-------------+------------+ 
    | 1   | d1   | 
    +-------------+------------+  
    | 2   | d2   | 
    +-------------+------------+ 
    | 2   | d3   | 
    +-------------+------------+ 

結果 數都相同父兒童ID和顯示所有主標識，如果孩子不具有主ID比0

+-------------+----------------------+ 
    |countparentIds in child| parentName  
    +-------------+----------------------+ 
    | 6      | a   | 
    +-------------+----------------------+ 
    | 2      | b   | 
    +-------------+----------------------+ 
    | 0      | c   | 
    +-------------+----------------------+ 

現在我的laravel雄辯就像下面。

$master = DB::table('parents') 
     ->select(array('parent.name as Name', DB::raw('COUNT(child.parent_id) as countparentids'))) 
     ->join('child', 'parent.id', '=', 'child.parent_id', 'left outer') 
     ->where(child.code,'d1') 
     ->orderBy('parent.name') 
     ->groupBy('parent.id') 
     ->groupBy('parent.name') 
     ->get(); 

現在我得到了結果，父表所有行，並計數具有父ID的子。

Answer 1

嘗試用CASE WHEN
像這樣

$ter = DB::table('parents') 
    ->leftjoin('child', 'parent.id', '=', 'child.parent_id') 
    ->select(array('parent.name as Name', DB::raw('CASE WHEN (child.code= "d1") THEN COUNT(child.parent_id) ELSE 0 END as countparentids'))) 
    ->orderBy('parent.name') 
    ->groupBy('parent.name') 
    ->get();