我需要从我的表中选择前20000,它有几列(数字,颜色等...),我需要在一个查询中从这些20000中得到红色的计数和蓝色的计数。
我知道如果我在临时表中插入前20000然后从临时表中选择红色计数然后从临时表中选择蓝色计数,我就能得到我想要的东西,但我需要这样做在一个查询中。
我尝试了以下但它给了我每个数字的计数,我需要总数..
SELECT top 20000 [number], count(color)
FROM [profile]
group by number
having color='red'
输出:
答案 0 :(得分:2)
您可以使用iif
:
select top 20000 [number]
, sum(iif([color] = 'red', 1, 0) as red_count
, sum(iif([color] = 'blue', 1, 0) as blue_count
from [profile]
group by [number]
或case
:
select top 20000 [number]
, sum(case when [color] = 'red' then 1 else 0 end) as red_count
, sum(case when [color] = 'blue' then 1 else 0 end) as blue_count
from [profile]
group by [number]
修改即可。在您更新了问题后,我猜您的查询应如下所示:
select t.[color]
, count(t.[color])
from (select top 20000 [color] from [profile]) t
group by t.[color]
答案 1 :(得分:1)
您可以使用嵌套查询:
select inner.color, count(*) from
(select top 20000 [number], color from [profile]) inner
group by inner.color
答案 2 :(得分:0)
SELECT top 20000 [number], count(color) as count_total,
sum(case when color='red' then 1 else 0 end) as count_red,
sum(case when color='blue' then 1 else 0 end) as count_blue
FROM [profile]
group by number