PHP内的代码如下:$sqlstr_max_vf = "select Max(vf) as Vmax_vf from (SELECT vf FROM tdata ORDER BY fkey desc )yy LIMIT $num"; $res_max_vf = mysql_query($sqlstr_max_vf,$con) or die("ddddd"); $pid_max_vf = mysql_result($res_max_vf,0,"Vmax_vf");
另外,在MYSQL可以执行。但是在程序里面不能执行。而且提交速度非常 慢!
select A as A_vf from (SELECT A FROM Adata ORDER BY fkey desc LIMIT $num)yy 和 select Max(vf) as Vmax_vf from (SELECT vf FROM tdata ORDER BY fkey desc )yy LIMIT $num 表达的意思不一样吧?limit在内部和外部,你想要查的到底是什么列?
把limit $num放()里面也试了,不行。谢谢了,能再帮忙看看?
我的code是这样的:$sqlstr_max_vf = "select Max(vf) as Vmax_vf from (SELECT vf FROM tdata ORDER BY fkey desc LIMIT $num )yy ";
$res_max_vf = mysql_query($sqlstr_max_vf,$con) or die("ddddd"); $pid_max_vf = mysql_result($res_max_vf,0,"Vmax_vf");
$pid_max_vf = mysql_result($res_max_vf,0,"Vmax_vf");
和
select Max(vf) as Vmax_vf from (SELECT vf FROM tdata ORDER BY fkey desc )yy LIMIT $num
表达的意思不一样吧?limit在内部和外部,你想要查的到底是什么列?
把limit $num放()里面也试了,不行。谢谢了,能再帮忙看看?
我的code是这样的:$sqlstr_max_vf = "select Max(vf) as Vmax_vf from (SELECT vf FROM tdata ORDER BY fkey desc LIMIT $num )yy ";
$res_max_vf = mysql_query($sqlstr_max_vf,$con) or die("ddddd");
$pid_max_vf = mysql_result($res_max_vf,0,"Vmax_vf");