mysql num rows fix PHP

Question

I have this code:

$ip_adresa = $_SERVER['REMOTE_ADDR'];
$query = mysql_query("SELECT * FROM IP WHERE IP='$ip_adresa'");

if(mysql_num_rows($query) > 0) {
    echo 'Do something';
} else {
    echo 'Do something';
}

I have error

Warning: mysql_num_rows() expects parameter 1 to be resource, boolean given in...

Answer 1

Function mysql_query returns FALSE on error. Your SQL statement appears to be incorrect, it is unclear what "IP" is, a column or a table.

Furthermore, as mentioned by Script47:

Warning This extension was deprecated in PHP 5.5.0, and it was removed in PHP 7.0.0. Instead, the MySQLi or PDO_MySQL extension should be used. See also MySQL: choosing an API guide and related FAQ for more information. Alternatives to this function include: mysqli_query() PDO::query()

http://php.net/manual/en/function.mysql-query.php

Answer 2

First of All mysql_* is deprecated in php from php 5.3 or 5.2 . So it's a bad idea to use that .

You should use PDO . Why PDO ? mysqli_* may be faster than PDO but PDO gives access to use wide range of databases . Most of the Frameworks use PDO because by this is the way they can give developers access to 12 databases in php very easily .

if you use PDO your query will be like this:

<?php


/**
*  Class description
*/
Class Connection {

private $host;
private $host_user;
private $host_pass;
private $db_name;
public  $db;

    function __construct(){
        # code...

        try {

        $this->host             = 'localhost';
        $this->host_user        = 'root';
        $this->host_pass        = '';
        $this->db_name          = 'your_database';

        //Main Connection script
        $this->db = new PDO('mysql:host='.$this->host.'; dbname='.$this->db_name, $this->host_user, $this->host_pass);
        $this->db->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION );
        $this->db->setAttribute( PDO::ATTR_EMULATE_PREPARES, 0 );
        $this->db->exec("SET CHARACTER SET utf8");

        } catch (PDOException $err){

            echo "harmless error message if the connection fails";
            $err->getMessage() . "<br/>";
            die();  //  terminate connection

        }

    }


}



?>

// Using namespace is a great choice but i'm doing that in a general your script.php

include_once 'connection_class.php';

class query extends Connection {

 // You need to call into your fille .. thant's it . safe query and safe // result :)
  public static function pdoQuery(){

      $query = $this->db->prepare("SELECT * FROM IP WHERE IP= :ip");
      $query->bindParam(':ip',$ip);
      $query->execute();
      return $query->rowCount();

  }

}