0

首先，为这个糟糕的标题道歉，我想不出更好的方式来表达我的问题。（欢迎提出更好的替代方案）

基本上我有一个带有“计数”列的表。我想将所有计数重置为零，但具有最高值的 10 行除外。我希望将它们重置为 0。

如何在不编写多个查询的情况下实现这一目标？

更新 我现在有如下查询

UPDATE covers AS t1 
  LEFT JOIN (SELECT t.cover_id 
               FROM covers t 
               ORDER BY t.cover_views DESC 
               LIMIT 10) AS t2 ON t2.id = t.id
   SET cover_views = 0
   WHERE t2.id IS NULL

我得到了错误#1054 - Unknown column 't2.id' in 'where clause'- 知道为什么吗？

我也尝试了以下相同的结果

UPDATE covers t1 
  LEFT JOIN (SELECT t.cover_id 
               FROM covers t 
               ORDER BY t.cover_views DESC 
               LIMIT 10) t2 ON t2.id = t.id
   SET t1.cover_views = 0
   WHERE t2.id IS NULL
4

3 回答 3

2

利用：

UPDATE TABLE t1 
  LEFT JOIN (SELECT t.id 
               FROM TABLE t 
           ORDER BY t.id DESC 
              LIMIT 10) t2 ON t2.id = t1.id
   SET TABLE.count = 0
 WHERE t2.id IS NULL
于 2010-09-01T21:26:46.423 回答
1

尝试：

update <table> t 
left outer join 
(
select id from <table> order by <counter> desc limit 10
) c on c.id = t.id 
set 
 <counter> = 0
where 
 c.id is null;
于 2010-09-01T21:28:25.543 回答
0

您可以使用子查询：

update A set count = 0 where A.id not in 
(select id from A order by count desc limit 10)
于 2010-09-01T21:20:34.533 回答