Question

在此查询中，我尝试选择用户已付款的金额：

SELECT *
from (select IFnull(t.diapason,'total') as diapason,
t.total_amount as total_amount 

FROM 
(SELECT p.user_id, p.amount as total_amount, CASE
when amount<=100 then '0-100'
when amount>100 then '100...' END AS diapason
FROM (SELECT distinct payments.user_id, SUM(amount) AS amount 
FROM payments inner JOIN (SELECT DISTINCT user_id FROM payments where 
     payment_time between '2000-01-01' and '2001-01-01') a ON 
payments.user_id = a.user_id 
GROUP BY payments.user_id) p) t  
GROUP BY diapason WITH ROLLUP) as t1  
ORDER BY total_amount desc;

但是我得到的结果是错误的。我应该更改什么才能找出2000年1月1日至2001年1月1日之间的工资总额。由于用户曾经付款，结果必须按组划分。

这些是表格活动和付款。

activity
user_id   login_time
1         2000-01-01
2         2000-03-01
....

payments
user_id     payment_time    amount
1          2000-05-04        10
1          2000-03-01        20
2          2000-04-05        5
...

通常，组由每个用户曾经支付的总金额组成。例如，如果他支付了50美元-他在“ 0-100”组中。如果他支付了500，那么他就属于“ 100 ...”组，但是现在我需要知道每个组中用户的付款总额。

谢谢您的帮助！

Answer 1

我认为您需要SUM或AVG之一：

SELECT user_id,
       SUM(Amount) `sum`,
       AVG(Amount) `avg`
FROM payments 
WHERE payment_time BETWEEN '2000-01-01' AND '2001-01-01'
GROUP BY ser_id

或此数（2000年1月1日至2001年1月1日之间Amount的总和除以特定用户的记录总数）：

SELECT user_id,
       SUM(CASE WHEN payment_time BETWEEN '2000-01-01' AND '2001-01-01' THEN Amount ELSE 0 END) / COUNT(*) `customAvg`
FROM payments 
WHERE payment_time BETWEEN '2000-01-01' AND '2001-01-01'
GROUP BY ser_id

Answer 2

如果我理解正确，则不需要所有这些子查询。简单的sum和group by应该做到：

SELECT t1.user_id, sum(t2.amount) as total, IF(sum(t2.amount)<=100, '0-100',  '100...') as grp 
FROM t1
INNER JOIN t2 on t1.user_id = t2.user_id
WHERE t2.payment_time between '2000-01-01' and '2001-01-01'
GROUP BY t1.user_id

如何选择某些“ id”的总和并按组划分结果

2 个答案: