Question

I have two tables in my database that I”m trying to use one Query to get data from both for a specific report.

Table one is “Movies” and it has these fields:

• Movies_ID
• Name
• Season

Table two is “Boxoffice” sales income for each movie:

• Boxoffice_ID
• Movies_ID
• Date
• Amount

I want to run a query to compare the opening weekends for each movie in a given season and return them as one dataset with the amounts collected added together. So I want to take each movie and get the first three days of box office for each film and add them up so that I get back a query like this

1. Movie A, 49.1 Million
2. Movie B, 42.2 Million
3. Movie C, 29.5 Million

Please note the amount collected only needs to output the number and I’ll take care of the formatting. I’m just having trouble figuring out how to only query the first three days of box office for each movie and adding them together.

I know I could run one query and get the movies with box office and then loop over that and re-query the database but I know that with a lot of movies that isn’t the most efficient way of doing things. I’m not sure if there is a way to do all of this (first three days of each movie added together) in one query but I wanted to see if someone with more advanced knowledge could help me out.

Answer 1

SELECT  a.Name, SUM(COALESCE(b.Amount,0)) totalAmount
FROM    Movies a
        LEFT JOIN BoxOffice b
            ON a.Movies_ID = b.Movies_ID
WHERE   b.date BETWEEN DATE_ADD(CURDATE(),INTERVAL -3 DAY) AND CURDATE()
GROUP BY a.Name

if the value of CURDATE() is 2012-11-06 (which is today), it will calculate from 2012-11-03 until 2012-11-06.

followup question, how do you calculate the date? by day? by week? or what?

UPDATE 1

SELECT  a.Name, SUM(COALESCE(b.Amount,0)) totalAmount
FROM    Movies a
        LEFT JOIN BoxOffice b
            ON a.Movies_ID = b.Movies_ID
        LEFT JOIN
        (
            SELECT  movies_ID, MIN(date) minDate
            FROM    BoxOffice
            GROUP BY Movies_ID
        ) c ON a.Movies_ID = c.Movies_ID
WHERE   DATE(b.date) BETWEEN DATE(c.minDate) AND 
                             DATE(DATE_ADD(c.minDate,INTERVAL 3 DAY))
GROUP BY a.Name