Delete query not working in php/MYSQL

Question

I have wrote a PHP script just to delete a single row from a MySQL DB by id. The value of id has taken from the $_POST of a button when clicked i tried different ways to pass that variable having the $_POST value but it doesn't worked. every thing seems fine i tried the same query with static value in the DB and that worked fine there. here is my complete code. Note: i also have tried $_GET and also tried '.$delete_id.' and '$delete_id'

    include ("db_conection.php");

    if (isset ( $_GET ['view'] )) {
        $view_id = $_GET ['view'];

        $query_run = null;

        $query1 = "SELECT * FROM question where testid ='" . $view_id . "'";
        $run = mysqli_query ( $conn, $query1 ); // here run the sql query.
        while ( $row = mysqli_fetch_array ( $run ) )            // while look to fetch the result
                                             // and store in a array $row.
        {

            echo '  

  <tr>
  <td>' . $row ['qid'] . '</td>
  <td>' . $row ['testid'] . '</td>
  <td>' . $row ['questions'] . '</td>
  <td>
  <a href="remove_question.php?del=' . $row ['qid'] . '" class = "btn btn-danger btn-block">Delete</a>

  </td>
  </tr>

        ';

        }

        if (isset ( $_POST ['del'] )) {
            $delete_id = $_POST ['del'];
            $delete_query = "Delete  from question WHERE qid='".$delete_id."'"; // delete
                                                                            // query

            // $run=mysqli_query($conn,$delete_query);
            $run = $conn->query ( $delete_query );
            if ($run) {
                // bootstrap class to open in the same window
                /*
                 * echo "<script>window.open('Admin Delete
                 * member.php','_self')</script>";
                 */

                echo "<script>window.open('remove_question.php','_self')</script>";

                echo '

<div align = "center" style = "margin-top:10px;" class = "alert alert-success">deleted...</div>

';
            } else {

                echo "deletion field";
            }

        }

    }

This has a whopping great SQL injection vulnerability in it - do not use this code! — halfer
– halfer, Commented Aug 30, 2016 at 10:15

Shailesh Chauhan · Accepted Answer · 2016-08-29 10:36:45Z

1

Just write your delete query outside of if block like below.

include ("db_conection.php");

if (isset ( $_GET ['view'] )) {
    $view_id = $_GET ['view'];

    $query_run = null;

    $query1 = "SELECT * FROM question where testid ='" . $view_id . "'";
    $run = mysqli_query ( $conn, $query1 ); // here run the sql query.
    while ( $row = mysqli_fetch_array ( $run ) )
    {
        echo ' <tr>  <td>' . $row ['qid'] . '</td>  <td>' . $row 'testid'] . '</td>  <td>' . $row ['questions'] . '</td>  <td>  <a href="remove_question.php?del=' . $row ['qid'] . '" class = "btn btn-danger btn-block">Delete</a>  </td>  </tr>    ';
    }
}
if (isset ( $_GET ['del'] )) {
    $delete_id = $_GET ['del'];
    $delete_query = "Delete  from question WHERE qid='".$delete_id."'"; // delete
                                                                    // query

    // $run=mysqli_query($conn,$delete_query);
    $run = $conn->query ( $delete_query );
    if ($run) {
        // bootstrap class to open in the same window
        /*
         * echo "<script>window.open('Admin Delete
         * member.php','_self')</script>";
         */

        echo "<script>window.open('remove_question.php','_self')</script>";

        echo '<div align = "center" style = "margin-top:10px;" class = "alert alert-success">deleted...</div>';
    } else {
        echo "deletion field";
    }

}

answered Aug 29, 2016 at 10:36

Shailesh Chauhan

5703 silver badges15 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Afaq Ahmad Over a year ago

thank you so much.. it works fine and perfect.. i have spend my whole day resolving this..

AssenKhan · Accepted Answer · 2016-08-29 09:56:38Z

1

 $delete_query = "Delete  from question WHERE qid='".$delete_id."'";

answered Aug 29, 2016 at 9:56

AssenKhan

5665 silver badges15 bronze badges

1 Comment

Afaq Ahmad Over a year ago

i have tried " '.$delete_id." '... but that your method " '.$delete_id." ' syntax is not correct

Naresh Kumar P · Accepted Answer · 2016-08-29 09:56:53Z

1

The Method to get the ID should be $_REQUEST

 <a href="remove_question.php?del=' . $row ['qid'] . '" class = "btn btn-danger btn-block">Delete</a>

Change the delete Query code like this since you are passing it in the URL based on $_REQUEST.

<?php
if (isset ( $_REQUEST ['del'] )) {
            $delete_id = $_REQUEST ['del'];
            $delete_query = "Delete  from question WHERE qid='".$delete_id."'"; // delete
            // $run=mysqli_query($conn,$delete_query);
            $run = $conn->query ( $delete_query );
            if ($run) {
                echo "<script>window.open('remove_question.php','_self')</script>";
                echo '
<div align = "center" style = "margin-top:10px;" class = "alert alert-success">deleted...</div>
';
            } else {
                echo "deletion field";
            }
        }
?>

answered Aug 29, 2016 at 9:56

Naresh Kumar P

4,2802 gold badges18 silver badges34 bronze badges

1 Comment

Naresh Kumar P Over a year ago

Put echo and exit the query after that. and check whether delete_id is passing

Collectives™ on Stack Overflow

Delete query not working in php/MYSQL

3 Answers 3

1 Comment

1 Comment

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

1 Comment

1 Comment

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related