错误的语法查询SQL

Question

我需要选择具有特定名称的用户：

mysql_query('select * from user where screen_name='.$userName.'');

任何人都可以在我错的地方帮助我？

Answer 1

是错误的sql：

mysql_query('select * from user where screen_name="'.$userName.'"');

Answer 2

mysql_query("select * from user where screen_name = '".$userName."';");

更好（在我看来）

$sql = "SELECT * FROM `user` WHERE `screen_name` = '".$userName."';";
mysql_query($sql);

更好 - 使用mysqli ....

Answer 3

mysql_query("select * from user where screen_name='$userName'");

尝试.....