AM71ui4s

1drop TABLE if EXISTS track_downloads;
2
3CREATE TABLE track_downloads  (
4	download_id  SERIAL,
5	track_id  INTEGER NOT NULL,
6	user_id INTEGER NOT NULL,
7	download_time timestamp without time zone NOT NULL
8);
9
10insert into track_downloads(track_id, user_id, download_time) VALUES
11(1, 1, TO_TIMESTAMP('2010-11-19', 'YYYY-MM-DD')), 
12(1, 2, TO_TIMESTAMP('2010-11-19', 'YYYY-MM-DD')), 
13(2, 1, TO_TIMESTAMP('2010-11-19', 'YYYY-MM-DD')), 
14(2, 2, TO_TIMESTAMP('2010-11-19', 'YYYY-MM-DD')), 
15(2, 3, TO_TIMESTAMP('2010-11-19', 'YYYY-MM-DD')),
16(1, 1, TO_TIMESTAMP('2010-11-18', 'YYYY-MM-DD')), 
17(1, 2, TO_TIMESTAMP('2010-11-18', 'YYYY-MM-DD')), 
18(2, 1, TO_TIMESTAMP('2010-11-20', 'YYYY-MM-DD')), 
19(2, 2, TO_TIMESTAMP('2010-11-20', 'YYYY-MM-DD')), 
20(2, 3, TO_TIMESTAMP('2010-11-20', 'YYYY-MM-DD'));
21
22SELECT count(user_id), download_count from(
23  select user_id, count(download_id) as download_count from track_downloads
24  where download_time = '2010-11-19'
25  group by user_id
26) as t
27group by download_count;
28
29
30