mysql - 我要检查子查询的值如何检查？

这是我在mysql中的更新查询

UPDATE userentries
SET User_Rank =
(
  SELECT
  urc.rankofentr as User_Rank
  from UserRankingsys as urc
  WHERE urc.entryid = userentries.id
  LIMIT 1
)
where userentries.id = 15

我想检查该部分返回的值

(
  SELECT
  urc.rankofentr as User_Rank
  from UserRankingsys as urc
  WHERE urc.entryid = userentries.id
  LIMIT 1
)

如果此子查询返回的值大于我要设置的值102，我该怎么做

最佳答案

您可以使用CASE

  SELECT case urc.rankofentr when > 20 then 20
                             else urc.rankofentr
         end as User_Rank
  from UserRankingsys as urc
  WHERE urc.entryid = userentries.id
  LIMIT 1

为你的sql

UPDATE userentries
SET User_Rank =
(
 SELECT case urc.rankofentr when > 20 then 20
                             else urc.rankofentr
         end as User_Rank
  from UserRankingsys as urc
  WHERE urc.entryid = userentries.id
  LIMIT 1
)
where userentries.id = 15;

关于mysql - 我要检查子查询的值如何检查？，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/34806187/