Question

Currently I’m struggling on retrieving top 10 records calculated by amount spend over a period of time.

MySQL table:

create table `payment_holder` (
    `user_id` int (11),
    `amount` Decimal (6),
    `date_added` datetime 
); 

Demo data:

insert into `payment_holder` (`user_id`, `amount`, `date_added`) values('4','3.75','2012-03-15 00:41:39');
insert into `payment_holder` (`user_id`, `amount`, `date_added`) values('5','32.20','2012-03-15 00:42:10');
insert into `payment_holder` (`user_id`, `amount`, `date_added`) values('6','32.20','2012-03-15 00:42:58');
insert into `payment_holder` (`user_id`, `amount`, `date_added`) values('7','0.89','2012-03-15 00:48:05');
insert into `payment_holder` (`user_id`, `amount`, `date_added`) values('8','3.75','2012-03-15 00:50:54');
insert into `payment_holder` (`user_id`, `amount`, `date_added`) values('4','3.75','2012-03-15 00:41:39');
insert into `payment_holder` (`user_id`, `amount`, `date_added`) values('5','32.20','2012-03-15 00:42:10');
insert into `payment_holder` (`user_id`, `amount`, `date_added`) values('6','32.20','2012-03-15 00:42:58');
insert into `payment_holder` (`user_id`, `amount`, `date_added`) values('7','0.89','2012-03-15 00:48:05');
insert into `payment_holder` (`user_id`, `amount`, `date_added`) values('8','3.75','2012-03-15 00:50:54');

I would like retrieve a result like the following it from this example:

user_id amount
------------------
6       64.40   
5       64.40   
4       7.5 
8       7.5 
7       1.78

So in short, which user_id has the highest amount of purchases based on date_added in 2012?

Answer 1

Have you tried something like this which will return all data for all years:

select user_id, sum(amount) Amount
from payment_holder
group by user_id
order by amount desc
limit 0, 10

See SQL Fiddle with Demo

But if you want to limit by year, you can add a WHERE clause which will apply the YEAR() function to the date_added field:

select user_id, sum(amount) Amount
from payment_holder
where year(date_added) = 2012
group by user_id
order by amount desc
limit 0, 10