Warning:mysql_fetch_array()expectsparameter1toberesource,booleangiveni解决办法

database = new MySql();
        $this->username = $u;
        $this->password = $p;
    }
    function register(){
        $pmd5 = md5($this->password.self::USERCONST);

        $sql = "insert into user_table (username,password) values('".$this->username."','".$pmd5."')";
        $database->setSQL($sql);
    }
    function logout(){
        echo "注销";
    }
    function login(){
        echo "登录";
    }
    function usercheck(){                                                                                    //密码加常量
        $sql = "select count(uid) as user from user_table where uid='".$this->username."'and password='".md5($this->password,self::USERCONST)."'";
        $query = $this->database->setSQL($sql);
        if($row = $this->database->select_array($query)){
            echo $row["user"];
        }
    }
}
?>

host = "localhost";
        $this->username = "root";
        $this->password = "";
        $this->database = "bkqs";
        $this->mysqlconnection();
     }
     function mysqlconnection(){
        $connection = mysql_connect($this->host,$this->username,$this->password) or die ("连接数据库失败");
        mysql_select_db($this->database,$connection) or die ("打开数据库失败");
        mysql_query("set names 'GBK'");
     }
     function setSQL($sql){
        return mysql_query($sql);
     }
     function select_array($query){
         return mysql_fetch_array($query);
     }
     function select_object($query){
         return mysql_fetch_object($query);
     }
     function close(){
         return mysql_close();
     }
 }
?>