Mysql query - JOINS and WHERE clause, beginner here :) - mysql

Question

having difficulties with a form and mysql. 3 tables, 1 sum of a tables values. The form provides the value to search, but it does not work with the "WHERE >= '$search_total_rating" being in the wrong place, i am doing something very wrong here.
$result = mysql_query("SELECT coffeeshops.*, services.*, ratings.*, sum(temp.total) as final_total FROM coffeeshops inner join services on coffeeshops.shop_id=services.shop_id
inner join ratings on coffeeshops.shop_id=ratings.shop_id
inner join (select SUM(comfort + service + ambience + friendliness + spacious)/(5) / COUNT(shop_id) AS total, shop_id FROM ratings GROUP BY shop_id) as temp on coffeeshops.shop_id=temp.shop_id WHERE >= '$search_total_rating'");
I do not fully understand this, but what i am trying to do is WHERE the total rating sum is >= selected rating. I am trying to access final_total which is not an actual column in my database, that is why SUM is being used to get the total rating for each shop. Hopefully it is a minor shuffle of the code. Thanks

Answer 1

You should use having instead of where
SELECT coffeeshops.*, services.*, ratings.*, sum(temp.total) as final_total
FROM coffeeshops inner join services on coffeeshops.shop_id=services.shop_id
inner join ratings on coffeeshops.shop_id=ratings.shop_id
inner join (
select SUM(comfort + service + ambience + friendliness + spacious)/5/ COUNT(shop_id) AS total, shop_id
FROM ratings GROUP BY shop_id)
as temp on coffeeshops.shop_id=temp.shop_id
having final_total >= '$search_total_rating'

Answer 2

You have already calculated your total in the subquery. No need for a second SUM().
SELECT coffeeshops.*
, services.*
, ratings.*
, temp.total as final_total
FROM coffeeshops
inner join services
on coffeeshops.shop_id = services.shop_id
inner join ratings
on coffeeshops.shop_id = ratings.shop_id
inner join
( select SUM(comfort + service + ambience + friendliness + spacious) / 5
/ COUNT(shop_id) AS total
, shop_id
FROM ratings
GROUP BY shop_id
) as temp
on coffeeshops.shop_id = temp.shop_id
WHERE temp.total >= '$search_total_rating'
You could also use a HAVING in the subquery:
SELECT coffeeshops.*
, services.*
, ratings.*
, temp.total as final_total
FROM coffeeshops
inner join services
on coffeeshops.shop_id = services.shop_id
inner join ratings
on coffeeshops.shop_id = ratings.shop_id
inner join
( select SUM(comfort + service + ambience + friendliness + spacious) / 5
/ COUNT(shop_id) AS total
, shop_id
FROM ratings
GROUP BY shop_id
HAVINGE total >= '$search_total_rating'
) as temp
on coffeeshops.shop_id = temp.shop_id