mysql 含有 ORDER BY id DESC LIMIT的查询语句 还能用 WHERE (1=1) 吗
SQL这样处理是没有问题的,在绝大多数的软件开发中,都是按照你这样的思路做的。但如果 commend = '{$uid}' 是个一定的条件,就可以替代 1=1;并且你题目中有需求两个查询条件同时输入的话怎么办,你可以修改下SQL语句拼接结构,如下:if($regtime != null ){$m = "(加个空格)AND regtime = '{$regtime}' AND commend = '{$uid}'";if($realname != null ){$n = "(加个空格)AND realname = '{$realname}' AND commend = '{$uid}'";$a = "SELECT * FROM `user` WHERE 1=1";@$a .= $m;@$a .= $n;@$a .= "(加个空格)ORDER BY id DESC LIMIT {$begin},{$pagesize}"$b = mysql_query($a);
mysql group by 能同时加几个where条件么
selectcount(if(isCheck=1,1,0)),count(if(isPay=1,1,0)),count(id)fromtablegroupbygroup;
count(if(isCheck=1,1,0))
if返回的是值,也就是说,最后count(1)或者count(0).这样能count出来么。我试过不行
不好意思,打错了
selectsum(if(isCheck=1,1,0)),sum(if(isPay=1,1,0)),sum(id)fromtablegroupbygroup;
标签:count,uid,mysqlorderbywhere,regtime,commend,id,realname From: https://blog.51cto.com/yetaotao/5800737