Question

I have been trying to figure this out for a while now and decided I’m not going to figure it out any time soon! Thanks for the help in advance. Love this place.

I have 2 tables

date:

date_id, user_id, cost, title, description

date_rating:

date_id, user_id, rating

I have multiple entries with the same date_id but different user_id‘s. In other words multiple ratings of the same date. The ratings are either 1 or -1. I want to add all the ratings together with the same date_id and then join that to my DATE table where date_id matches. So that I have a column called rating on the table DATE. This way I can sort by rating. Sounds easy but it has proven to be not so easy. I guess DBA is not my thing!

edit: MySQL client version: mysqlnd 5.0.8-dev – 20102224 – $Revision: 310735 $

Answer 1

Can’t you just use something like this? I’m no expert at MySQL, mind you (I’m more a SQL Server guy):

SELECT
     date_id, user_id, cost, title, description,
     (SELECT SUM(rating) FROM date_rating dr WHERE dr.date_id = d.date_id) AS 'Rating'
FROM 
     date d

Just a correlated subquery to get the sum of ratings for each date specified by it’s date_id ?