楼主想要的应该是这样:$query="SELECT * FROM user where user_name='".$name."'";
$sql="SELECT * FROM user where user_name='".$name."'";
$sql="SELECT * FROM user where user_name=$name";php中使用双引号可直接引用变量!
$sql="SELECT * FROM user where user_name={$name}";
$sql = "SELECT * FROM post WHERE fid = $ffid ORDER BY id DESC";
先谢过各位。补充下,双引号是可以识别变量,但是不带引号。所以where条件里面的字符串需要另外加引号。如果 $xxx = "csdn"; 那么$sql = "SELECT * FROM post WHERE fid = csdn ORDER BY id DESC"; 这样csdn少个引号就不对了。必须$xxx = '"'.csdn.'"'; 才对。
sql="select username from ".$table." where adminid='1'"
sql="select * from ".$table." where username='$user'"
如:sql='select * from '.$table.' where username='.$user;
楼上说的也是正确的,不过没有说的这么玄乎,关键就只有一点:双引号识别变量,单引号不识别变量。单引号会把括起来的部分全部失败为字符串。
$sql="SELECT * FROM user where user_name='".$name."'";
$sql="SELECT * FROM user where user_name={$name}";
FROM post
WHERE fid = $ffid
ORDER BY id DESC";
那么$sql = "SELECT *
FROM post
WHERE fid = csdn
ORDER BY id DESC";
这样csdn少个引号就不对了。必须$xxx = '"'.csdn.'"';
才对。