Question

我有一个带有两个连接的mySQL语句：

SELECT a.userID,  sum(b.score) as totalScore, c.userName FROM b
  Inner Join a on b.noteID = a.noteID
  Inner Join user on c.userID =  a.userID
  Where totalScore != 0
  group by a.userID  order by totalScore desc

但是当我运行查询时，它无法破译我用as

标记的总和

LIMIT 0, 1000   Error Code: 1054. Unknown column 'totalScore' in 'where clause' 0.18

Answer 1

使用having子句

  select a.userID, c.userName, 
         sum(b.score) as totalScore
  FROM b
  Inner Join a on b.noteID = a.noteID
  Inner Join user on c.userID =  a.userID
  group by a.userID, c.userName 
  having totalScore != 0
  order by totalScore desc

您无法使用select子句

where

totalScore是一个引用整个组而不只是单个记录的值，因此您必须将其放入having
您不应选择c.userName，因为它既未汇总，也未汇总在group by子句中。在strict模式下，MySQL抛出错误，其他数据库引擎将始终抛出错误

sum（）as x在mySQL的where语句中看不到x

1 个答案: