SQL Server 选择多个分组

Question

我有两个描述用户及其付款的表:

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'));

表 test_users:

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

表 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

我需要做一个用户统计来显示:

1. 用户名
2. 一段时间内的总费用
3. 最后一次的日期用户的事件(一般，不是一段时间)。

例如，以 15-18.12.12 期间为例，我希望得到以下结果:

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

我试过以下查询:

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;

但是 last_activity 的结果是错误的，因为它也在日期范围内:

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

请提出解决方案。

Answer 1

在我处理我的问题时，似乎弹出了其他几个答案，但无论如何它都在这里。这里有一个有效的 sql fiddle :http://sqlfiddle.com/#!3/14808/6

基本上，无论日期范围如何，您都需要一个查询来提取最大日期。我选择将其作为相关子查询来执行。

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