Notice: Undefined offset: 0....override/classes/Category.php on line 18

Question

i use prestashop 1.6.1.12 I use php 7.1

I have this error message 10 times:

Notice: Undefined offset: 0....override/classes/Category.php on line 18

category.php content is :

<?php
/**
*
*add function for image2 for for class product.php
*
**/
class Category extends CategoryCore
{
    public static function getProductsImgSupp($product_id)
    {
            $sql = '
            SELECT id_image, id_product from `'._DB_PREFIX_.'image`
            WHERE id_product="'.$product_id.'"
            ORDER BY `position` ASC
            LIMIT 1,1
            ';
            $result = Db::getInstance()->ExecuteS($sql);
            return $result[0]['id_product'].'-'.$result[0]['id_image'];
    }
}

Is there a way to correct this error ?

Answer 1

Your sql does not return any records.

2 Reasons for this:

1. There are no images in the table ...image (which may be correct)

OR

2. The product_id which is getting passed to your method is not correct.

How to fix?

Case 1:

$result = Db::getInstance()->ExecuteS($sql);

if (empty($result)) {
    return null; // you may have to deal with this null if you arent already
}

return $result[0]['id_product'].'-'.$result[0]['id_image'];

Case 2:

Check the code which calls getProductsImgSupp to see if the right id is passed.