Get previous X days of revenue for each group - mysql

Question

Here is my table
CREATE TABLE financials (
id INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY,
CountryID VARCHAR(30) NOT NULL,
ProductID VARCHAR(30) NOT NULL,
Revenue INT NOT NULL,
cost INT NOT NULL,
reg_date TIMESTAMP
);
INSERT INTO `financials` (`id`, `CountryID`, `ProductID`, `Revenue`, `cost`, `reg_date`) VALUES
( 1, 'Canada', 'Doe' , 20, 5, '2010-01-31 12:01:01'),
( 2, 'USA' , 'Tyson' , 40, 15, '2010-02-14 12:01:01'),
( 3, 'France', 'Keaton', 80, 25, '2010-03-25 12:01:01'),
( 4, 'France', 'Keaton',180, 45, '2010-04-24 12:01:01'),
( 5, 'France', 'Keaton', 30, 6, '2010-04-25 12:01:01'),
( 6, 'France', 'Emma' , 15, 2, '2010-01-24 12:01:01'),
( 7, 'France', 'Emma' , 60, 36, '2010-01-25 12:01:01'),
( 8, 'France', 'Lammy' ,130, 26, '2010-04-25 12:01:01'),
( 9, 'France', 'Louis' ,350, 12, '2010-04-25 12:01:01'),
(10, 'France', 'Dennis',100,200, '2010-04-25 12:01:01'),
(11, 'USA' , 'Zooey' , 70, 16, '2010-04-25 12:01:01'),
(12, 'France', 'Alex' , 2, 16, '2010-04-25 12:01:01');
For each product and date combination, I need to get the revenue for previous 5 days. For instance, for Product ‘Keaton’, the last purchase was on 2010-04-25, it will only sum up revenue between 2010-04-20 to 2010-04-25 and therefore it will be 210. While for "Emma", it would return 75, since it would sum everything between 2010-01-20 to 2010-01-25.
SELECT ProductID, sum(revenue), reg_date
FROM financials f
Where reg_date in (
SELECT reg_date
FROM financials as t2
WHERE t2.ProductID = f.productID
ORDER BY reg_date
LIMIT 5)
Unfortunately, when i use either https://sqltest.net/ or http://sqlfiddle.com/ it says that 'LIMIT & IN/ALL/ANY/SOME subquery' is not supported. Would my query work or not?

Answer 1

Your query is on the right track, but probably won't work in MySQL. MySQL has limitations on the use of in and limit with subqueries.
Instead:
SELECT f.ProductID, SUM(f.revenue)
FROM financials f JOIN
(SELECT ProductId, MAX(reg_date) as max_reg_date
FROM financials
GROUP BY ProductId
) ff
ON f.ProductId = ff.ProductId and
f.reg_date >= ff.max_reg_date - interval 5 day
GROUP BY f.ProductId;
EDIT:
If you want this for each product and date combination, then you can use a self join or correlated subquery:
SELECT f.*,
(SELECT SUM(f2.revenue)
FROM financials f2
WHERE f2.ProductId = f.ProductId AND
f2.reg_date <= f.reg_date AND
f2.reg_date >= f.reg_date - interval 5 day
) as sum_five_preceding_days
FROM financials f;

Answer 2

After some trials I ended up with some complex query, that I think it solves your problem
SELECT
financials.ProductID, sum(financials.Revenue) as Revenues
FROM
financials
INNER JOIN (
SELECT ProductId, GROUP_CONCAT(id ORDER BY reg_date DESC) groupedIds
FROM financials
group by ProductId
) group_max
ON financials.ProductId = group_max.ProductId
AND FIND_IN_SET(financials.id, groupedIds) BETWEEN 1 AND 5
group by financials.ProductID
First I used group by financials.ProductID to count revenues by products. The real problem you are facing is eliminating all rows that are not in the top 5, for each group. For that I used the solution from this question, GROUP_CONCAT and FIND_IN_SET, to get the top 5 result without LIMIT. Instead of WHERE IN I used JOIN but with this, WHERE IN might also work.
Heres the FIDDLE