在php中连接到mysql时，query_id没有返回任何内容

Question

My query is:

$sqlCommand="select `ID` from `freecomputermarket`.`members` where `UserName`='$this->_userName';";

i am usign XAMPP as apache server and i am working on port (89)

this class responsible for database connection:

<?php
class MySql
{
    private $_link_Id,$_query_Id,$_serverName,$_userName,$_password,$_dbName,$_rowNum;

    public function __construct()
    {
       $this->_serverName="localhost";
       $this->_userName="root";
       $this->_password="";
       $this->_dbName="freecomputermarket";
    }
    public function connect()
    {
       $this->_link_Id=mysql_connect($this->_serverName,$this->_userName,$this->_password);
       if(!$this->_link_Id)
       {
          exit("The Connect is Failed");
       }
       $db_select=mysql_select_db($this->_dbName,$this->_link_Id);
       if(!$db_select)
       {
          exit("Can't Select DataBase");
       }
    }
    public function query($sqlcommand)
    {
       $sqlcommand= addslashes($sqlcommand);
       //echo $sqlcommand;
       $this->_query_Id=mysql_query($sqlcommand,$this->_link_Id);
       exit($this->_query_Id);//print it to check if it is available.
       if(!$this->_query_Id)
          exit("Query failed");
       $this->_rowNum=mysql_affected_rows();
    }
    public function getRow()
    {
       if($this->_rowNum)
       {
          return mysql_fetch_assoc($this->_query_Id);
       }
    }
    public function getAllRows()
    {
       $arr=array();
       $count=0;
       while($count<$this->_rowNum)
       {
          array_push($arr,$this->GetRow());
          $count++;
       }
       return $arr;
    }
    public function getAffectedRowsNumber()
    {
       return $this->_rowNum;
    }
}   
?>

this code for connecting to the mysql dbms and execute queries. when printing $_link_Id ,it has a value. when printing $_query_Id ,it has nothing ?

Answer 1

Problem is here

$sqlcommand= addslashes($sqlcommand);

Don't use addslashes.

use like this

//$sqlcommand= addslashes($sqlcommand);
$this->_query_Id=mysql_query($sqlcommand,$this->_link_Id);