Delete multiple rows with checkbox form DB table - php

Question

Here is my code -
<?php
$host = "localhost"; // Host name
$username = ""; // Mysql username
$password = ""; // Mysql password
$db_name = "test"; // Database name
$tbl_name = "test_mysql"; // Table name
// Connect to server and select databse.
mysql_connect("$host", "$username", "$password") or die("cannot connect");
mysql_select_db("$db_name") or die("cannot select DB");
$sql = "SELECT * FROM $tbl_name";
$result = mysql_query($sql);
$count = mysql_num_rows($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="4" bgcolor="#FFFFFF"><strong>Delete multiple rows in mysql</strong></td>
</tr>
<tr>
<td align="center" bgcolor="#FFFFFF">#</td>
<td align="center" bgcolor="#FFFFFF"><strong>Id</strong></td>
<td align="center" bgcolor="#FFFFFF"><strong>Name</strong></td>
<td align="center" bgcolor="#FFFFFF"><strong>Lastname</strong></td>
<td align="center" bgcolor="#FFFFFF"><strong>Email</strong></td>
</tr>
<?php
while ($rows = mysql_fetch_array($result)) {
?>
<tr>
<td align="center" bgcolor="#FFFFFF"><input name="checkbox[]" type="checkbox"
id="checkbox[]" value="<? echo $rows['id']; ?>">
</td>
<td bgcolor="#FFFFFF"><? echo $rows['id']; ?></td>
<td bgcolor="#FFFFFF"><? echo $rows['name']; ?></td>
<td bgcolor="#FFFFFF"><? echo $rows['lastname']; ?></td>
<td bgcolor="#FFFFFF"><? echo $rows['email']; ?></td>
</tr>
<?php
}
?>
<tr>
<td colspan="5" align="center" bgcolor="#FFFFFF"><input name="delete" type="submit" id="delete"
value="Delete"></td>
</tr>
<?
// Check if delete button active, start this
if ($delete) {
for ($i = 0; $i < $count; $i++) {
$del_id = $checkbox[$i];
$sql = "DELETE FROM $tbl_name WHERE id='$del_id'";
$result = mysql_query($sql);
}
// if successful redirect to delete_multiple.php
if ($result) {
echo "<meta http-equiv="refresh" content="0;URL = delete_multiple . php">";
}
}
mysql_close();
?>
</table>
</form>
</td>
</tr>
</table>
What I want is that data rows of the table, whose checkboxes are checked,
to be Deleted from the Database on click of Delete button.
I have tried these but it doesn't work well.
Please suggest me regarding the above code how to delete the selected rows
from DB, onclick of Delete button.

Answer 1

Theoretically it should work, but I have not tested
<?php
$host = 'localhost'; // Host name
$username = ''; // Mysql username
$password = ''; // Mysql password
$db_name = 'test'; // Database name
$tbl_name = 'test_mysql'; // Table name
// Connect to server and select databse.
mysql_connect($host, $username, $password) or die('cannot connect');
mysql_select_db($db_name) or die('cannot select DB');
$sql = 'SELECT * FROM `'.$tbl_name.'`';
$result = mysql_query($sql);
?>
<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="4" bgcolor="#FFFFFF"><strong>Delete multiple rows in mysql</strong> </td>
</tr>
<tr>
<td align="center" bgcolor="#FFFFFF">#</td>
<td align="center" bgcolor="#FFFFFF"><strong>Id</strong></td>
<td align="center" bgcolor="#FFFFFF"><strong>Name</strong></td>
<td align="center" bgcolor="#FFFFFF"><strong>Lastname</strong></td>
<td align="center" bgcolor="#FFFFFF"><strong>Email</strong></td>
</tr>
<?php while ($rows = mysql_fetch_array($result)): ?>
<tr>
<td align="center" bgcolor="#FFFFFF"><input name="need_delete[<? echo $rows['id']; ?>]" type="checkbox" id="checkbox[<? echo $rows['id']; ?>]" value="<? echo $rows['id']; ?>"></td>
<td bgcolor="#FFFFFF"><? echo $rows['id']; ?></td>
<td bgcolor="#FFFFFF"><? echo htmlspecialchars($rows['name']); ?></td>
<td bgcolor="#FFFFFF"><? echo htmlspecialchars($rows['lastname']); ?></td>
<td bgcolor="#FFFFFF"><? echo htmlspecialchars($rows['email']); ?></td>
</tr>
<?php endwhile; ?>
<tr>
<td colspan="5" align="center" bgcolor="#FFFFFF"><input name="delete" type="submit" id="delete" value="Delete"></td>
</tr>
<?php
// Check if delete button active, start this
if ( ! empty($_POST['delete'])) {
foreach ($_POST['need_delete'] as $id => $value) {
$sql = 'DELETE FROM `'.$tbl_name.'` WHERE `id`='.(int)$id;
mysql_query($sql);
}
header('Location: delete_multiple.php'); exit();
}
mysql_close();
?>
</table>
</form>
</td>
</tr>
</table>

Answer 2

Tested version:
Change lines 45-55 to
if($_POST['delete']){
$i = 0;
while(list($key, $val) = each($_POST['checkbox'])) {
$sql = "DELETE FROM $tbl_name WHERE id='$val'";
mysql_query($sql);
$i += mysql_affected_rows();
}
// if successful redirect to delete_multiple.php
if($i > 0){
echo '<meta http-equiv="refresh" content="0;URL=delete_multiple.php">';
}
}
The file should start with "<?php" and it is considered bad style to mix "<?" and "<?php" in the same file (lines 31-35 and line 43).
EDIT: forgot the $_POST[''] from $delete on line 45. If you have the register_globals ini-directive on, it does not matter (It's still dangerous and bad style though).