Mysql Count（*）作为Total WHERE Total？

Question

SELECT
  Id, QId, UName, Ans, Date, COUNT(*) * 10 as Total
FROM
  question
WHERE
  COUNT(*)
DESC
GROUP BY
  UName

不起作用:(

Answer 1

我认为您想过滤组。 使用HAVING COUNT(*)代替WHERE ：

SELECT Id, QId, UName, Ans, Date, Count(*) * 10 as Total
FROM question
GROUP BY UName
HAVING Count(*)

如果您要按元素数量对组进行排序，请使用ORDER BY ：

SELECT Id, QId, UName, Ans, Date, Count(*) * 10 as Total
FROM question
GROUP BY UName
ORDER BY Count(*) DESC