最大值，最小值成一個T-SQL查詢

Question

我有表：

create table dbo.call (
subscriber_name varchar(64)  not null 
, event_date  datetime not null 
, event_cnt  int  not null 
) 

需要編寫一個返回每個查詢訂戶最小的日期事件的數量是可能的，而最大的年月日時事件的數量很少，事件的數量也很少。

結果：

subscriber_name | min_date | max_event_cnt | max_date | min_event_cnt 
---------------------------------------------------------------------------------- 
Subscriber1  | 20091012 | 15 20061012 | 10   | 
---------------------------------------------------------------------------------- 
Subscriber2  | 20080301 | 20 20090513 | 8   | 
---------------------------------------------------------------------------------- 

Answer 1

嘗試以下方法：

SELECT 
    t1.subscriber_name, 
    min_date, 
    max_event_cnt, 
    max_date, 
    min_event_cnt 
FROM 
(
    SELECT 
    subscriber_name, 
    MIN(event_date) AS min_date, 
    MAX(event_cnt) AS max_event_cnt 
    FROM 
    dbo.call 
    GROUP BY 
    subcriber_name 
) t1 
JOIN 
(
    SELECT 
    subscriber_name, 
    MAX(event_date) AS max_date, 
    MIN(event_cnt) AS min_event_cnt 
    FROM 
    dbo.call 
    GROUP BY 
    subcriber_name 
) t2 
ON t1.subscriber_name = t2.subscriber_name 

的