php mysql查询表中最后设置的行数

Question

我想构建一个mysql_query ，它只给我一个插入table新rows ， where condition就像....

SELECT (LAST 5) FROM `x`  WHERE `USER_KEY` = '$RK' ORDER BY `dd` DESC 

此数据将在json中解析，否则我将获得所有数据并循环投掷。

Answer 1

你可以颠倒顺序并获得前5个。这与获得最后5个并且相反排序相同

SELECT * FROM `x`  WHERE `USER_KEY` = '$RK' ORDER BY `dd` ASC limit 5

或者，如果你需要desc命令，你可以做

select * from (SELECT * FROM `x`  
               WHERE `USER_KEY` = '$RK' 
               ORDER BY `dd` asc 
               limit 5) as x 
order by `dd` desc