PHP message: Notice: Trying to access array offset - php

Question

I'm stuck on next:
I get this error: Notice: Trying to access array offset on the value of type null in C:\xampp\htdocs\admin_area\view_rel.php on line 64. How to solve this error and what kind of error is?
My PHP code:
<?php
$i = 0;
$get_rel = "select * from bundle_product_relation";
$run_rel = mysqli_query($con,$get_rel);
while($row_rel = mysqli_fetch_array($run_rel)){
$rel_id = $row_rel['rel_id'];
$rel_title = $row_rel['rel_title'];
$bundle_id = $row_rel['bundle_id'];
$product_id = $row_rel['product_id'];
$get_p = "select * from products where product_id='$product_id'";
$run_p = mysqli_query($con,$get_p);
$row_p = mysqli_fetch_array($run_p);
$p_title = $row_p['product_title'];
$get_b = "select * from products where product_id='$bundle_id'";
$run_b = mysqli_query($con,$get_b);
$row_b = mysqli_fetch_array($run_b);
$b_title = $row_b['product_title'];
$i++;
?>
<tr>
<td><?php echo $i; ?></td>
<td><?php echo $rel_title; ?></td>
<td><?php echo $p_title; ?></td>
<td><?php echo $b_title; ?></td>
<td>Delete</td>
<td>Edit</td>
</tr>
<?php } ?>
Error is on line 64 and that line of code is $p_title = $row_p['product_title'];.
Database is for products:
1. product_id
2.p_cat_id
3.cat_id
4.manufacturer_id
5.date
6.product_title
7.product_url
8.product_img1
9.product_img2
10.product_img3
11.product_price
12.product_psp_price
13.product_desc
14.product_features
15.product_video
16.product_keywords
17.product_label
18.status
Database for bundle_product_relation:
1.rel_id
2.rel_title
3.product_id
4.bundle_id
Where im wrong? Thanks all

Answer 1

Answer on this question is:
I haved error on line 64 and that line of code is $p_title = $row_p['product_title'];.
Solution for me is:
From: $p_title = $row_p['product_title']; to:
$p_title = isset($row_p['product_title']);