Question

$sql=mysql_query("select * from user where name=$username");错误，跪求原因

<?php
$link=mysql_connect("localhost","root","root");
mysql_select_db("oldboys",$link);
mysql_query("set names gb2312");
$username='testname';
$sql=mysql_query("select * from user where name=$username");
if($sql) echo 'ok';
else echo 'error';
?>
只显示error，我有数据库：
id name pwd
1 testname pwdtest
什么情况呢？求大家指教

Answer 1

$sql=mysql_query("select * from user where name=' $username'");
或
$sql=mysql_query("select * from user where name=" + $username);
两者都可以
$username要么用单引号要么分离出来

Answer 2

$sql=mysql_query("select * from user where name='" + $username + "'");
你试试

Answer 3

<?php
$link=mysql_connect("localhost","root","root");
mysql_select_db("oldboys",$link);
mysql_query("set names gb2312");
$username='testname';
$sql=mysql_query("select * from user where name='{$username}'");
if($sql) echo 'ok';
else echo 'error';
?>

Answer 4

$sql=mysql_query("select * from user where 'name'=$username");
这样就好了，name是mysql专有名词，不能随便用