查询数据库出错！

请检查是否输入了非法字符或报告新疆热线：http://www.xjline.com.cn
执行的语句为: SELECT * FROM house_users WHERE (uid= && username="")
MySQL返回信息: 1064: You have an error in your SQL syntax. Check the manual that corresponds to your MySQL server version for the right syntax to use near '&& username="")' at line 1