CODEWITHSUNDEEP
phpmysqli
Sonics McClaine
Sonics McClaine

Reputation: 51

Variables won't show after delete query is not successful

I am working on a delete a Brand query. If the Brand has any products in it it will not delete else the brand will get deleted. When working on a Brand without product, it is getting deleted but when working with Brand with product it shows the error message that it cannot be deleted but the data related to that brand on the delete page is not showing after I click on delete button. All variables is not getting printed or echoing anything, just the error message is there with Delete button and other HTML code.

<?php 
require_once('../auth.php');
require_once('../constants.php'); 
$errors = array();
$id = $_GET['id'];
$select = mysqli_query($conn,"SELECT * FROM brands Where `id` = '".$id."'");
$row = mysqli_fetch_array($select);
$brandname = $row['brand_name'];
if(!isset($_GET['id']))
{
    header("Location: http://localhost/php/brands/index.php");
}
if(isset($_POST['submit'])){
    $selectProducts = mysqli_query($conn,"SELECT * FROM `products` Where `brand_id` = '".$id."'");
    $select = mysqli_query($conn,"SELECT * FROM brands Where `id` = '".$id."'");
    $selectrow = mysqli_fetch_array($select);
    $brandName = $selectrow['brand_name'];
    if($row = mysqli_num_rows($selectProducts) > 0)
    {
        $errors[] = "Cannot Delete this brand, it has products in it.";     
    }
    else{
    $id = $_GET['id'];
    $sql ="DELETE FROM `brands` WHERE `brands`.`id` = '".$id."'";
    $result = mysqli_query($conn,$sql) or die(mysqli_error($conn));
    if($result){
        echo $msg = $id." is deleted.";
        header("Location: http://localhost/wsp/php/brands/index.php");
        }
        else{
            $msg = $id." cannot be deleted.";
        }
    }
}
?>

the form is 

<form method="post" action="delete.php?id=<?php echo $id; ?>">
    <h2 class="panel-title">Delete <?php echo $brandname; ?>?</h2>

    <div class="messages">
        <?php if($errors){
            foreach ($errors as $key => $value) {
                echo '<div class="alert alert-warning" role="alert">
                <i class="glyphicon glyphicon-exclamation-sign"></i>
                '.$value.'</div>';
            }
        }?>

    </div>
    <img src="<?php echo ASSETS;?><?php echo $row['brand_logo']; ?>" style="max-width:195px"/>
    <h2><?php echo strtoupper($row['brand_name']); ?></h2>
    <br><?php echo $row['brand_type']; ?><br><?php echo $row['status']; ?>
    <button type="submit" id="submit" name="submit"  class="btn btn-danger">Delete</button>
    <button name="reset" type="reset" class="btn btn-default">Cancel</button>
</form>

I would like to know why all variables in $row[''] are showing empty after the query says it cannot delete the brand? Why is it not showing variables?

Upvotes: 0

Views: 39

Answers (1)

Bart Friederichs
Bart Friederichs

Reputation: 33533

There is lot of (bad) stuff happening in your code, but I think your problem boils down to this:

if ($row = mysqli_num_rows($selectProducts) > 0)

There, you assign true or false to $row, instead of the row data. You should change that into something like

if (mysqli_num_rows($selectProducts) > 0) {
} else {
   $row = mysqli_fetch_array($selectProducts);
}

On the bad stuff:

  1. Use prepared statements, instead of building your queries with the . operator.
  2. Use correct indentation, so the code is more readable. (Code is more often read than written).
  3. Try to structure is a little better. Do one thing at the time, not four things intertwined.

Upvotes: 1

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