Only getting one result from sub select in inner join in mysql - mysql

Question

Hi I have run into a dilemma, I am doing this query:
SELECT GROUP_CONCAT(DISTINCT(ca.category_name) SEPARATOR ', ') AS categories, pr.promo_name, pr.add_value_text, c.contract_id, c.cmeal_plan, c.cmin_markup, c.civa, c.tax_include, c.hotel_id, hi.hname, hi.hstars, im.image_file, pl.plan_name, ra.price
FROM contracts AS c
INNER JOIN hotel_info AS hi ON hi.hotel_id = c.hotel_id AND hi.destination_id = '6460'
INNER JOIN images AS im ON im.foreign_id = hi.hotel_id
INNER JOIN meal_plan AS pl ON pl.plan_code = c.cmeal_plan AND pl.lang = '1'
INNER JOIN hotel_categories AS hc ON hc.hotel_id = hi.hotel_id
INNER JOIN categories AS ca ON ca.category_code = hc.category_code AND ca.lang = '1'
LEFT JOIN
(SELECT
r.hotel_id, AVG(r.double) AS price
FROM
rates AS r ) AS ra
ON ra.hotel_id = hi.hotel_id
LEFT JOIN promotions AS pr ON pr.hotel_id = hi.hotel_id AND FIND_IN_SET(c.contract_id, pr.contract_id) > 0 AND pr.book_start <= '2012-11-01' AND pr.book_end >= '2012-11-02' AND travel_start <= '2012-11-23' AND travel_end >= '2012-11-30' AND pr.lang = '1'
WHERE c.cstart <= '2012-11-01' AND c.cend >= '2012-11-01'
AND hi.status = '1'
AND im.type ='1'
GROUP BY hi.hotel_id
I am getting all the desired results except for the sub select query.. each hotel has a price but it is only giving me back one result and the rest are all null. Is there an error in my query? If any additional information is needed please let me know and thank you in advance for any help!

Answer 1

You are missing the GROUP BY in your subquery, so MySQL will only return one-value. If you want all hotel_id's then you need to GROUP BY that field:
SELECT GROUP_CONCAT(DISTINCT(ca.category_name) SEPARATOR ', ') AS categories,
pr.promo_name,
pr.add_value_text,
c.contract_id,
c.cmeal_plan,
c.cmin_markup,
c.civa,
c.tax_include,
c.hotel_id,
hi.hname,
hi.hstars,
im.image_file,
pl.plan_name,
ra.price
FROM contracts AS c
INNER JOIN hotel_info AS hi
ON hi.hotel_id = c.hotel_id
AND hi.destination_id = '6460'
INNER JOIN images AS im
ON im.foreign_id = hi.hotel_id
INNER JOIN meal_plan AS pl
ON pl.plan_code = c.cmeal_plan
AND pl.lang = '1'
INNER JOIN hotel_categories AS hc
ON hc.hotel_id = hi.hotel_id
INNER JOIN categories AS ca
ON ca.category_code = hc.category_code
AND ca.lang = '1'
LEFT JOIN
(
SELECT r.hotel_id, AVG(r.double) AS price
FROM rates AS r
GROUP BY r.hotel_id <-- add a GROUP BY hotel_id then you will get avg() for each hotel
) AS ra
ON ra.hotel_id = hi.hotel_id
LEFT JOIN promotions AS pr
ON pr.hotel_id = hi.hotel_id
AND FIND_IN_SET(c.contract_id, pr.contract_id) > 0
AND pr.book_start <= '2012-11-01'
AND pr.book_end >= '2012-11-02'
AND travel_start <= '2012-11-23'
AND travel_end >= '2012-11-30'
AND pr.lang = '1'
WHERE c.cstart <= '2012-11-01'
AND c.cend >= '2012-11-01'
AND hi.status = '1'
AND im.type ='1'
GROUP BY hi.hotel_id