Question

I have two tables describing users and their payments:

CREATE TABLE test_users
(id int IDENTITY NOT NULL,
name varchar(25),
PRIMARY KEY (id));

CREATE TABLE test_payments
(id int IDENTITY NOT NULL,
user_id int NOT NULL,
money money NOT NULL,
date datetime NOT NULL,
PRIMARY KEY (id));

INSERT INTO test_users (name) 
VALUES ('john');

INSERT INTO test_users (name) 
VALUES ('peter');

INSERT INTO test_payments (user_id, money, date)
VALUES (1, $1, CONVERT(datetime, '15.12.2012'));

INSERT INTO test_payments (user_id, money, date)
VALUES (1, $2, CONVERT(datetime, '16.12.2012'));

INSERT INTO test_payments (user_id, money, date)
VALUES (2, $1, CONVERT(datetime, '16.12.2012'));

INSERT INTO test_payments (user_id, money, date)
VALUES (2, $3, CONVERT(datetime, '17.12.2012'));

INSERT INTO test_payments (user_id, money, date)
VALUES (1, $1, CONVERT(datetime, '19.12.2012'));

Table test_users:

id  name
-------------
1   john
2   peter

Table test_payments:

id  user_id money   last_activity
---------------------------------------
1   1   1.0000  2012-12-15
2   1   2.0000  2012-12-16
3   2   1.0000  2012-12-16
4   2   3.0000  2012-12-17
5   1   1.0000  2012-12-19

I need to make a users statistic which will show me :

1. username
2. total fee for a period of time
3. the date of the last
   user’s activity (general, not for a time period).

For example taking the period 15-18.12.12 I expect the following results:

name    total    last_activity
--------------------------------
peter   $4       2012-12-17
john    $3       2012-12-19

I’ve tried the following query:

SELECT u.*, SUM(p.money) total, MAX(p.date) last_activity
FROM test_users u
JOIN test_payments p
ON u.id= p.user_id
WHERE p.date BETWEEN CONVERT(datetime, '15.12.2012') AND CONVERT(datetime, '18.12.2012')
GROUP BY u.id, u.name
ORDER BY total DESC;

but getting wrong result for last_activity as it is also in the date range:

id  name    total   last_activity
--------------------------------
2   peter   4.0000  2012-12-17
1   john    3.0000  2012-12-16

Please suggest a solution.

Answer 1

Looks like a couple of other answers popped up while I worked on mine, but here it is anyhow. There is a working sql fiddle here: http://sqlfiddle.com/#!3/14808/6

Basically, you need a query to pull the max date regardless of the date range. I chose to do this as a correlated subquery.

SELECT 
  u.id,
  u.name,
  SUM(IsNull(money,0)) as TotalMoneyInRange,
  (SELECT max(date) FROM test_payments where user_id = u.id) AS LastPaymentOverAll
FROM test_users AS u
LEFT JOIN test_payments AS p
ON u.id = p.user_id
WHERE 
  p.date IS NULL OR
  p.date between 
  CAST('12-11-2012' AS datetime) --range begin
  and 
  CAST('12-16-2012' as datetime) --range end
GROUP BY u.id, u.name