Get number of products sold by name using group by

Question

I have similar table:

CREATE TABLE ForgeRock
    (`id` int, `name` varchar(100), `price` decimal(10,2),`soldtime` datetime)
;

With similar values (random characters in name field)

INSERT INTO ForgeRock
    (`id`, `name`, `price`,`soldtime`)
VALUES
    (1, 'OpenIDM..', 10,'2015-10-11'),
    (2, 'OpenAM....', 20,'2016-1-9'),
    (3, 'OpenDJ...', 30,'2010-1-1'),
    (2, 'OpenAM...', 20,'2016-12-9'),
    (2, 'OpenAM.....', 20,'2016-11-9'),
    (2, 'OpenDJ...', 20,'2016-10-9')
;

Now I am trying to get the count of each product sold using group by:

SELECT *,Count(*) as sc FROM `ForgeRock` Group by name

But I am getting random result(most products are missing). I think it is due to restriction on group by that all non aggregated columns must be part of group by. What is the alternate solution?

Thanks.

Answer 1

Since you just want product and count, you should only ask for product and count rather than "*"

SELECT name, count(*) AS sc FROM ForgeRock GROUP BY name

If you want more "group" data, such as the average price, add it to the list of items selected:

SELECT name, count(*) AS sc, avg(price) AS ap 
FROM ForgeRock 
GROUP BY name

If you want other non-group data you also need to add it to the GROUP BY clause

SELECT name, DATE(soldtime), count(*) AS sc, avg(price) AS ap 
FROM ForgeRock 
GROUP BY name, DATE(soldtime)

This would give you counts and average prices by day.