How to Delete Multiple Rows Using Checkboxes in PHP: Addressing Common Errors and Ensuring Successful Execution?

Delete Multiple Rows by Selecting Checkboxes Using PHP: Troubleshooting Common Errors

When deleting multiple rows from a MySQL database table using PHP, selecting links using checkboxes requires careful coding to ensure successful execution. This code snippet offers a solution to a common issue:

<code class="php">
  
    <title>Links Page</title>
  
  
    <h2 id="Choose-and-delete-selected-links">Choose and delete selected links.</h2> 
    <?php $dbc = mysqli_connect('localhost','root','admin','sample') or die('Error connecting to MySQL server');
      $query = "select * from links ORDER BY link_id";
      $result = mysqli_query($dbc,$query) or die('Error querying database');
      $count=mysqli_num_rows($result);
    ?>
    <table width="400" border="0" cellspacing="1" cellpadding="0">
      <tr>
        <td>
          <form name="form1" method="post" action="">
            <table width="400" border="0" cellpadding="3" cellspacing="1" bgcolor="#CCCCCC">
              <tr>
                <td bgcolor="#FFFFFF"> </td>
                <td colspan="3" bgcolor="#FFFFFF">
                  <strong>Delete multiple links</strong>
                </td>
              </tr>
              <tr>
                <td align="center" bgcolor="#FFFFFF">#</td>
                <td align="center" bgcolor="#FFFFFF">
                  <strong>Link ID</strong>
                </td>
                <td align="center" bgcolor="#FFFFFF">
                  <strong>Link Name</strong>
                </td>
                <td align="center" bgcolor="#FFFFFF">
                  <strong>Link URL</strong>
                </td>
              </tr> 
              <?php while ($row=mysqli_fetch_array($result)) {
              ?>
              <tr>
                <td align="center" bgcolor="#FFFFFF">
                  <input name="checkbox[]" type="checkbox" value="<?php echo $row['link_id']; ?>">
                </td>
                <td bgcolor="#FFFFFF"> <?php echo $row['link_id']; ?> </td>
                <td bgcolor="#FFFFFF"> <?php echo $row['link_name']; ?> </td>
                <td bgcolor="#FFFFFF"> <?php echo $row['link_url']; ?> </td>
              </tr> 
              <?php }
              ?> 
              <tr>
                <td colspan="4" align="center" bgcolor="#FFFFFF">
                  <input name="delete" type="submit" value="Delete">
                </td>
              </tr>
            </table>
          </form>
        </td>
      </tr>
    </table>    
    <?php // Check if delete button active, start this
      if(isset($_POST['delete']))
      {
        $checkbox = $_POST['checkbox'];
        for($i=0; $i<count($checkbox); $i++) {
          $del_id = $checkbox[$i];
          $sql = "DELETE FROM links WHERE link_id='$del_id'";
          $result = mysqli_query($dbc, $sql); // Pass the database connection here
        }
        // if successful redirect to view_links.php 
        if($result){
          echo '<meta http-equiv="refresh" content="0;URL=view_links.php">';
        }
      }
      mysqli_close($dbc);
    ?>
  
</code>

The fix:

1. Treat the checkbox name as an array: name="checkbox[]" instead of name="checkbox".
2. Pass the $dbc database connection to each mysqli_query call, as shown in $result = mysqli_query($dbc, $sql);.

With these modifications, the code should correctly delete multiple rows based on the selected checkboxes.

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