mysql +更新前n个 [英] mysql + update top n

问题描述

我有这样的查询:

update  table
set     status = 1
where   status = 2;     

但是我只想在前400位执行此操作.我尝试添加"limit 0，400"(就像我在查询中那样)，但这没有用.我做了一些搜索，而mysql似乎不像SQL Server那样支持TOP(n)命令.

but I'd only like to do this to the top 400. I tried adding a 'limit 0, 400' (like I would in a query) but that didn't work. I did some searching and mysql doesn't seem to support the TOP(n) command as sql server does.

知道我该怎么做吗?

供将来参考，我使用以下样式进行选择，效果很好:

edit: for future reference, I was using the following style for selects, which worked fine:

select  * 
from    table
where   ... limit 0, 400;

，但是在更新中，无论出于何种原因，它都不会与"0"一起使用.我会认为这种行为不一致且模棱两可，但是，哦.

but in the update it wouldn't work with the "0, " for whatever reason. I would consider this inconsistent and ambiguous behaviour, but oh well.

推荐答案

UPDATE  table
SET     status = 1
WHERE   status = 2
ORDER BY id
LIMIT 400

已在MySQL 5.2.0-falcon-alpha-community-nt-log中签入，确认可以正常工作.

Checked in MySQL 5.2.0-falcon-alpha-community-nt-log, confirmed working.

在您的情况下，LIMIT 0, 400中的0不起作用.

In your case it's 0 in LIMIT 0, 400 that does not work.

您不能使用UPDATE的LIMIT中的下限.

You cannot use the lower bound in UPDATE's LIMIT.

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