如何组合多个SQL查询

Question

我是SQL的新手，我正在尝试弄清楚如何将多个查询放入六个项目的相同结果中。

我想组合的查询是：

SELECT TOP 2 * 
FROM tablename 
WHERE (time >= '20180226 21:00' AND channelname = 'A') 
ORDER BY time ASC 

SELECT TOP 2 * 
FROM tablename 
WHERE (time >= '20180226 21:00' AND channelname = 'B') 
ORDER BY time ASC 

SELECT TOP 2 * 
FROM tablename 
WHERE (time >= '20180226 21:00' AND channelname = 'C') 
ORDER BY time ASC 

唯一改变的是ChannelName，我确信有一种方法可以做到这一点，但我对SQL的语法技能只能说是有限的，我被卡住了。

Answer 1

Select * from (SELECT TOP 2 * 
FROM   tablename 
WHERE ( time >= '20180226 21:00' 
        AND channelname = 'A' ) ORDER  BY time ASC )t1
UNION ALL 

Select * from (SELECT TOP 2 * 
FROM   tablename 
WHERE ( time >= '20180226 21:00' 
        AND channelname = 'B' ) ORDER  BY time ASC )t2
UNION ALL

Select * from (SELECT TOP 2 * 
FROM   tablename 
WHERE ( time >= '20180226 21:00' 
        AND channelname = 'C' ) 
ORDER  BY time ASC )t3