Check if child data exists before deleting parent - php

Question

I have news_Category and news table, here every news comes under one category,so before deleting new_category I want to display user a msg that child news exists in this category so u are not allowed to delete, If there are no child news than a confirm alert to user that "do u really want to delete".If he confirms the news category gets deleted.
HTML STUFF
<?php echo "<a style='color:red;''
href='delete.php?delete=$values[category_id]&
img=$values[category_image]'><i class='fas fa-trash-alt'></i></a>"; ?>
if ($_GET['msgError']) {
echo "<script>alert('First Delete The News Than Category');</script>";
}
if ($_GET['msg']) {
?>
<?php
}
?>
DELETE.PHP
if (isset($_GET['delete'])) {
$id= $_GET['delete'];
$img=$_GET['img'];
$obj=new commands();
$obj->delete_category($id,$img);
}
Delete Function
function delete_category($id,$img)
{
$stmt = $this->con->prepare("SELECT category_id FROM nm_news where category_id='$id'");
$stmt->execute();
$result = $stmt->fetchAll(PDO::FETCH_ASSOC);
if ($result) {
header('Location: news_category.php?msgError=' . urlencode(base64_encode("First Delete The News Than Category")));
} else {
$sql = $this->con->prepare("DELETE FROM `nm_category` WHERE category_id=:id");
$sql->bindParam(':id', $id);
$sql->execute();
unlink("uploads/" . $img);
header('Location: news_category.php?msg="confirm"');
$this->con = null;
}
}
I am not able to make to logic here, how can I check whether the child news exists so i can display error msg and if there is no child news how to show confirm alert to allow delte

Answer 1

You need to check to see if the result is empty.
Something like this:
function delete_category($id,$img)
{
$stmt = $this->con->prepare("SELECT category_id FROM nm_news where category_id='$id'");
$stmt->execute();
$result = $stmt->fetchAll(PDO::FETCH_ASSOC);
if (empty($result)) {
header('Location: news_category.php?msgError=' . urlencode(base64_encode("First Delete The News Than Category")));
} else {
$sql = $this->con->prepare("DELETE FROM `nm_category` WHERE category_id=:id");
$sql->bindParam(':id', $id);
$sql->execute();
unlink("uploads/" . $img);
header('Location: news_category.php?msg="confirm"');
$this->con = null;
}
}
Edit due to extra details request
On the front end you just need to display the GET msgError like this:
<?php isset($_GET['msgError']) ? echo url_decode(base64_decode($_GET['msgError'])) : '' ?>
Where you want to show the message text.