Delete multiple rows by selecting checkboxes using PHP

I want to delete multiple rows from MYSQL database. I have created this delete.php file to select various links and delete them using checkboxes.

<html>
<head>

<title>Links Page</title>

</head>

<body>

<h2>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">&nbsp;</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 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">&nbsp;</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>



<?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'";
$result = mysqli_query($sql);
}
// if successful redirect to delete_multiple.php 
if($result){
echo "<meta http-equiv=\"refresh\" content=\"0;URL=view_links.php\">";
}
 }

mysqli_close($dbc);

?>

</table>
</form>
</td>
</tr>
</table>

</body>

</html>

This doesn't seem to delete any row. My data is populated in the table. I guess the problem is with the PHP code. Please help me out here.

Edwin Alex

You should treat it as an array like this,

<input name="checkbox[]" type="checkbox" value="<?php echo $row['link_id']; ?>">

Then only, you can take its count and loop it for deletion.

You also need to pass the database connection to the query.

$result = mysqli_query($dbc, $sql);

Yours did not include it:

$result = mysqli_query($sql);

Use array notation like name="checkbox[]" in your input element. This will give you $_POST['checkbox'] as array. In the query you can utilize it as

$sql = "DELETE FROM links WHERE link_id in ";
$sql.= "('".implode("','",array_values($_POST['checkbox']))."')";

Thats one single query to delete them all.

Note: You need to escape the values passed in $_POST['checkbox'] with mysql_real_escape_string or similar to prevent SQL Injection.

user3654452

Delete Multiple checkbox using PHP Code

<input type="checkbox" name="chkbox[]  value=".$row[0]."/>
<input type="submit" name="delete" value="delete"/>
<?php
if(isset($_POST['delete']))
{
 $cnt=array();
 $cnt=count($_POST['chkbox']);
 for($i=0;$i<$cnt;$i++)
  {
     $del_id=$_POST['chkbox'][$i];
     $query="delete from $tablename where Id=".$del_id;
     mysql_query($query);
  }
}

<?php $sql = "SELECT * FROM guest_book";
                            $res = mysql_query($sql);
                            if (mysql_num_rows($res)) {
                            $query = mysql_query("SELECT * FROM guest_book ORDER BY id");
                            $i=1;
                            while($row = mysql_fetch_assoc($query)){
                            ?>


<input type="checkbox" name="checkboxstatus[<?php echo $i; ?>]" value="<?php echo $row['id']; ?>"  />

<?php $i++; }} ?>


<input type="submit" value="Delete" name="Delete" />

if($_REQUEST['Delete'] != '')
{
    if(!empty($_REQUEST['checkboxstatus'])) {
        $checked_values = $_REQUEST['checkboxstatus'];
        foreach($checked_values as $val) {
            $sqldel = "DELETE from guest_book WHERE id = '$val'";
           mysql_query($sqldel);

        }
    }
}

Something that sometimes crops up you may/maynot be aware of

Won't always be picked up by by $_POST['delete'] when using IE. Firefox and chrome should work fine though. I use a seperate isntead which solves the problem for IE

As for your not deleting in your code above you appear to be echoing out 2x sets of check boxes both pulling the same data? Is this just a copy + paste mistake or is this actually how your code is?

If its how your code is that'll be the problem as the user could be ticking one checkbox array item but the other one will be unchecked so the php code for delete is getting confused. Either rename the 2nd check box or delete that block of html surely you don't need to display the same list twice ?

 $deleted = $_POST['checkbox'];
 $sql = "DELETE FROM $tbl_name WHERE id IN (".implode(",", $deleted ) . ")";

来源：https://stackoverflow.com/questions/14475096/delete-multiple-rows-by-selecting-checkboxes-using-php

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