php - 为什么聚合函数在我的 laravel SQL 查询中不起作用？

Question

$year = date("y"); 
for($i=1;$i<=12;$i++) 
{ 
   $MonthlyReceive = DB::table('order_items') ->whereBetween('created_at',array($year.'-'.$i.'-1',$year.'-'.$i.'-31')) ->select(DB::raw('sum(price*quantity)'))->where('quantity','<','0');
   return $MonthlyReceive; 
}

// table name "order_items"
// id |product_id |quantity |price |order_id

Answer 1

您无需循环即可按月明智地获取汇总数据。

   $MonthlyReceive = DB::table('order_items')
                ->select(DB::raw('sum(price*quantity) as amnt'))
                ->whereRaw('date(created_at) between "'.$year.'-01-01" and "'.$year.'-12-31"')
                ->where('quantity','<','0')
                ->groupBy(DB::raw("date_format(created_at, '%Y-%M')"));

只需使用带有聚合功能的group by即可。