同一张表中的MySQL子查询

Question

我有一张收集客户付款的表。我想从前3名客户那里得到每个客户的付款。

下面的查询获得每个客户每天每小时的总付款。下面

SELECT 
    hour(received) as hr, 
    login, 
    count(*) as total 
FROM 
    payment 
WHERE 
    received >= date("2011-02-24") 
AND 
    received <date("2011-02-25") 
AND 
    PAYMENT_BATCH_FILE_ID is null 
GROUP BY 
    hr, 
    client_id 
ORDER BY 
    hr, 
    total DESC 

查询获得前3名的客户端为每一个客户在一个小时内

SELECT 
    hour(received) as hr, 
    login, 
    count(*) as total 
FROM 
    payment 
WHERE 
    received >=date("2011-02-24") 
AND 
    received < date("2011-02-25") 
AND 
    PAYMENT_BATCH_FILE_ID is null 
AND 
    hour(received)="3" 
GROUP BY 
    hr, 
    client_id 
ORDER BY 
    hr, 
    total DESC 
LIMIT 3 

如何将两者结合起来的查询获得前3名的客户，使每个小时支付？

谢谢。

Answer 1

这是一个复杂的问题。参考此链接http://www.xaprb.com/blog/2006/12/07/how-to-select-the-firstleastmax-row-per-group-in-sql/

祝你好运！