Mysql变量无法通过php mysql查询工作

我有这个问题：

$query = " 

 SET @points := -1;
 SET @num := 0;

 SELECT `id`,`rank`,
 @num := if(@points = `rank`, @num, @num + 1) as `point_rank`
 FROM `said`
 ORDER BY `rank` *1 desc, `id` asc";

我正在使用来自PHP的这个查询;给我这个错误：

You have an error in your sql Syntax; check the manual that corresponds to your MysqL server version for the right Syntax to use near ‘SET @num := 0;

如果我在PHPmyadmin SQL查询面板中复制并粘贴该代码,它可以正常工作,但是从PHP代码行开始它不起作用,看起来设置Vars时会出现问题.

解决方法:

您是否尝试使用CROSS JOIN而不是在单独的SET中设置变量：

$query = " 

SELECT `id`,
  `rank`,
  @num := if(@points = `rank`, @num, @num + 1) as `point_rank`
FROM `said`
CROSS JOIN (SELECT @points:=-1, @num:=0) c
ORDER BY `rank` *1 desc, `id` asc";