Question

你好！

我的SQL任务有些麻烦，也许有人可以帮我解决这个问题。

我们有2个表：订单和供应商。需要准备一份包含供应商名称，发货项目和总订单百分比的表格。

我几乎完成了整个任务，但是过滤了3个供应商中有2个订单数量高于平均值的问题。

以下是任务说明：选择出货量高于平均水平的出货单（到“发件人”栏），他们发货的订单数量（到“商品”栏目发送“）和从总金额（到列 “配额”，值必须为'％'符号）

所以这是我的问题：

SELECT Shippers.ShipperName AS 'Sender', COUNT(*) AS 'Item_Sent',
COUNT(*)/(SELECT COUNT(*) FROM Orders) * 100 AS "Quota"
FROM Orders
JOIN Shippers ON Shippers.ShipperID=Orders.ShipperID
GROUP BY ShipperName
HAVING Item_Sent > (SELECT AVG(Item_Sent) from Orders);

HAVING出现问题... - 订单金额高于平均值时，它不会选择3个供应商中的2个。

Answer 1

您不应该为列别名使用引号，但最终应该使用引用：

  SELECT Shippers.ShipperName AS `Sender`, COUNT(*) AS `Item_Sent`,
  COUNT(*)/(SELECT COUNT(*) FROM Orders) * 100 AS "Quota"
  FROM Orders
  JOIN Shippers ON Shippers.ShipperID=Orders.ShipperID
  GROUP BY ShipperName
  HAVING Item_Sent > (SELECT AVG(Item_Sent) from Orders);

您也可以尝试不使用别名

  SELECT Shippers.ShipperName, COUNT(*),
  COUNT(*)/(SELECT COUNT(*) FROM Orders) * 100
  FROM Orders
  JOIN Shippers ON Shippers.ShipperID=Orders.ShipperID
  GROUP BY ShipperName
  HAVING COUNT(*) > (SELECT AVG(Item_Sent) from Orders);

SQL选择Count和AVG

1 个答案: