MySQL query, add new alias - php

Question

I have a mysql query using for search script and i need to add another field (like SPV.term alias) This code is tell me an Error Number: 1054 Unknown column 'S.id' in 'on clause'.
$query = "
SELECT
SP.url,
SP.id,
S.name,
SP.hit,
SP.hot,
SP.action,
SP.id,
SP.smallimage,
SP.mainmodimage,
(SELECT
stock
FROM shop_product_variants
WHERE shop_product_variants.product_id = S.id
AND stock > 0
LIMIT 1) as stock,
(SELECT
price
FROM shop_product_variants
WHERE shop_product_variants.product_id = S.id
OR shop_product_variants.product_id = S.id
AND stock = 0
LIMIT 1) as price,
(SELECT
id
FROM shop_product_variants
WHERE shop_product_variants.product_id = S.id
OR shop_product_variants.product_id = S.id
AND stock = 0
LIMIT 1) as v_id,
(SELECT
old_price
FROM shop_product_variants
WHERE shop_product_variants.product_id = S.id
AND stock > 0
LIMIT 1) as old_price
FROM shop_products_i18n S,
shop_product_variants SPV
INNER JOIN shop_products SP
ON SP.id = S.id
WHERE SP.active = 1
AND S.name LIKE '%" . $get . "%'
OR SP.url LIKE '%" . $get . "%'
OR SPV.term LIKE '%" . $get . "%'
GROUP BY S.id
ORDER BY stock DESC
";

Answer 1

This is your from clause:
FROM shop_products_i18n S,
shop_product_variants SPV INNER JOIN
shop_products SP
ON SP.id = S.id
The problem is that you are mixing old-style joins and new-style joins. A simple rule: Never use a commas in the from clause.
I think you really mean:
FROM shop_products_i18n S INNER JOIN
shop_products SP
ON SP.id = S.id
Because you don't use SPV anywhere else in the outer query, except for the where clause. That condition should probably go into each of the subqueries.
By the way, you can fix the original problem by replacing the , with cross join:
FROM shop_products_i18n S CROSS JOIN
shop_product_variants SPV INNER JOIN
shop_products SP
ON SP.id = S.id
Although , and cross join both perform cartesian products, they behave differently in the FROM clause in terms of precedence. The problem that you have with the , is that the precedence rules say the following INNER JOIN is parsed first -- so the columns in S are not available.