Cannot delete the value in a database

[mark103]

Hi guys,

 

I am recent working on my php to delete the information in a database. When I insert the value in the url bar something is like: www.mysite.com/delete.php?myfavorites=what ever it is&user=test. When I inserted the value in the url bar, it did not search for the value in a database to delete it while match with the username in the url bar.

 

 

<?php
session_start();
    define('DB_HOST', 'localhost');
    define('DB_USER', 'mydbuser');
    define('DB_PASSWORD', 'mydbpass');
    define('DB_DATABASE', 'mydbname');


$link = mysql_connect(DB_HOST, DB_USER, DB_PASSWORD);
    if(!$link) {

die('Failed to connect to server: ' . mysql_error());
    }

    $db = mysql_select_db(DB_DATABASE);
    if(!$db) {

die("Unable to select database");
    }

   function clean($var){

return mysql_real_escape_string(strip_tags($var));
    }
    $favorites = clean($_GET['favorites']);
    $username = clean($_GET['user']);


if($favorites == '' && $username == '') {
   // both are empty
   $errmsg_arr[] = 'Favorites are missing.';
   $errflag = true;

    if($errflag) {
  $_SESSION['ERRMSG_ARR'] = $errmsg_arr;
  echo implode('<br />',$errmsg_arr);
   }
   else {

$insert = array();
if(isset($_GET['favorites'])) {
    $insert[] = 'favorites = \'' . clean($_GET['favorites']) . '\'';
}
if(isset($_GET['username'])) {
    $insert[] = 'username = \'' . clean($_GET['username']) . '\'';
}


if (count($insert)>0) {
   $names = implode(',',$insert);


if($favorites && $username) {

mysql_query("DELETE valuedata FROM favorites WHERE username='$username'");
$deleted = mysql_affected_rows();
if($deleted > 0) {
    echo("The value in favorites are deleted");
    } else {
        echo("failed");
    }
    }else{
   echo("failed");
   }
}
}
mysql_close($link);
?>

 

 

If you know how to delete the value in a database for each row while it match with the username in the url, please say so as i would like to know how to do it.

 

Any advise would be much appreciated.

 

Thanks,

Mark

[Pikachu2000]

Use mysql_error. Echo things to see what's happening in your code. 

[SergeiSS]

It seems that you have a problem in a logic... Have a look. I don't change your code. I just change a style of you code

<?php 
session_start();
    define('DB_HOST', 'localhost');
    define('DB_USER', 'mydbuser');
    define('DB_PASSWORD', 'mydbpass');
    define('DB_DATABASE', 'mydbname');


$link = mysql_connect(DB_HOST, DB_USER, DB_PASSWORD);
if(!$link) 
{
  die('Failed to connect to server: ' . mysql_error());
}

$db = mysql_select_db(DB_DATABASE);
if(!$db) 
{
  die("Unable to select database");
}

function clean($var)
{
  return mysql_real_escape_string(strip_tags($var));
}
    
   
$favorites = clean($_GET['favorites']);
$username = clean($_GET['user']);


if($favorites == '' && $username == '') 
{
    // both are empty
    $errmsg_arr[] = 'Favorites are missing.';
    $errflag = true;

    if($errflag) 
    {
      $_SESSION['ERRMSG_ARR'] = $errmsg_arr;
      echo implode('<br />',$errmsg_arr);
    }
    else 
    {
      $insert = array();
      if(isset($_GET['favorites'])) 
      {
         $insert[] = 'favorites = \'' . clean($_GET['favorites']) . '\'';
      }
      if(isset($_GET['username'])) 
      {
         $insert[] = 'username = \'' . clean($_GET['username']) . '\'';
      }

      if (count($insert)>0) {
      $names = implode(',',$insert);

      if($favorites && $username) 
      {

        mysql_query("DELETE valuedata FROM favorites WHERE username='$username'");
        $deleted = mysql_affected_rows();
        if($deleted > 0) 
        {
          echo("The value in favorites are deleted");
        } 
        else 
        {
          echo("failed");
        }
      }
      else
      {
        echo("failed");
      }
    }
} 
mysql_close($link);
?>

 

You put brackets in a very random positions. I put them in correct places. I mean 'correct places' == 'correct distance from the line beginning'. Now it's clear that if this condition ($favorites == '' && $username == '') is not true you don't have a code to process it!!!

 

Also it looks funny :

    $errflag = true;

    if($errflag) 
    {....