php - php mysql 更新限制

Question

我想更新 mysql 数据库， where directory = 0，然后5 of records将哪个值更新0为art.

解释：

id    |   directory
1     |   fashion
2     |   0    //update here into 'art'
3     |   travel
4     |   fashion
5     |   0    //update here into 'art'
6     |   0    //update here into 'art'
7     |   travel
8     |   0    //update here into 'art'
9     |   0    //update here into 'art'
10    |   0    //this is 6th record, do not update, leave the value as '0'.
11    |   fashion

这个更新代码对吗？谢谢。

mysql_query("UPDATE articles SET directory = 'art' WHERE directory ='0' LIMIT 5");

Answer 1

你的语法很好。

我将添加一个 order by 子句（可以肯定）

ORDER BY `Id`

查询

UPDATE articles SET directory = 'art' WHERE directory ='0' ORDER BY id LIMIT 5

Answer 2

你的查询对我来说似乎没有错。

但请注意，您可能还想指定一个order by子句，以确定哪些是五个“第一”项：

update articles
set directory = 'art'
where directory = '0'
order by id
limit 5

仅供参考：更新语法