SQL query to get value from referenced table - php

Question

I have two tables called mg_product and mg_product_user_property.
In mg_product there are 3 columns: id, title, price as
In mg_product_user_property table product_id corresponds with id column in mg_product table.
So my goal is to get the value of property_id of "15", which in the picture above will be "Mediatek".
This is my SQL:
$sql = "SELECT *
FROM mg_product AS products
INNER JOIN mg_product_user_property AS properties
ON products.id = properties.product_id
WHERE title LIKE '%$search%')";`
PHP:
$resultSet = DB::query($sql);
if ($resultSet->num_rows > 0) {
while ($rows = $resultSet->fetch_assoc()) {
$title = $rows['title'];
$price = $rows['price'];
}
} else {
$output = "No results";
}
Now I need to assign to a php variable the value of property_id=15 so I will be able to print "Mediatek" on my website. How can I achieve that? Sorry for my English.

Answer 1

You are pretty close to what you want, but a couple things are going to either be a mess, or unwanted. So, since there are different ways one can go with this, I will only present a very stripped example (and am INTENTIONALLY leaving out a bunch of code here).
You may not want to do a JOIN like that in the initial search, as for each property, it will also return another of the same product. So looping through that will result in dozens of the same product.
However, if _ALL_YOU_WANT_ is to show the Product Title, Price, and Property 15... you can reduce some headwork with a simpler query:
SELECT p.title, p.price, pr.value
FROM mg_product AS p
LEFT JOIN mg_product_user_property AS pr
ON p.id = pr.product_id AND pr.property_id = 15
WHERE p.title LIKE '%$search%'
The LEFT JOIN means if the property doesn't exist, it will still return the product. But with an empty property value. And this should not return dozens of the same product for every other property in the table.
--
The OTHER way you could go about doing it, using the SQL query you already have (and the dozens of results of the same product it will return), you can alter your php loop like so:
$found_products = array();
while ($row = $resultSet->fetch_assoc()) {
if ($row['property_id'] == 15) {
$found_products[$row['product_id']] = array(
'title' => $row['title'],
'price' => $row['price'],
'prop' => $row['value']
);
}
}
// now you have a clean array of found products that have the property
--
Also I am forced to point out that you should use a prepared statement here, replacing inserting $search directly into the code. But showing you all of how to do that is beyond the scope of this question/answer.