[英]SQL How to PIVOT table using common table expression and dynamic SQL
I have this SQL query which groups searches by month: 我有此SQL查询按月分组搜索:
; with Mth (st, nd) as (
select DATEADD (M, datediff (m, 0,'2012-09-01'), 0),
DATEADD (M, DATEDIFF (m, 0, '2012-09-01') + 1, 0)
union all
select DATEADD (m, 1, st),
DATEADD (m, 1, nd)
from Mth
where nd <= DATEADD (m, datediff (m, 0, getdate()), 0)
)
select MONTH(Mth.st) Month,
COUNT(S.QRY_ID) Searches
FROM Mth
LEFT JOIN SEARCHES S
on Mth.st <= S.CREATED
and Mth.nd > S.CREATED
GROUP BY YEAR(Mth.st), MONTH(Mth.st)
ORDER BY 1,2
The result appears like this: 结果显示如下:
Month | Searches
---------------------
9 | 21
10 | 32
11 | 18
I'm trying to figure out how to use PIVOT
to achieve this: 我试图弄清楚如何使用PIVOT
实现此目的:
9 | 10 | 11
-----------------------
21 | 32 | 18
Could anyone please explain to me how to do it? 谁能告诉我怎么做?
You can use something like this: 您可以使用如下形式:
; with Mth (st, nd) as (
select DATEADD (M, datediff (m, 0,'2012-09-01'), 0),
DATEADD (M, DATEDIFF (m, 0, '2012-09-01') + 1, 0)
union all
select DATEADD (m, 1, st),
DATEADD (m, 1, nd)
from Mth
where nd <= DATEADD (m, datediff (m, 0, getdate()), 0)
)
select *
from
(
select MONTH(Mth.st) Month,
COUNT(S.QRY_ID) Searches
FROM Mth
LEFT JOIN SEARCHES S
on Mth.st <= S.CREATED
and Mth.nd > S.CREATED
GROUP BY YEAR(Mth.st), MONTH(Mth.st)
) src
pivot
(
sum(searches)
for month in ([9], [10], [11])
) piv
See SQL Fiddle with Demo 参见带有演示的SQL Fiddle
If you have an unknown number of months to transform, then you can use dynamic sql similar to this: 如果您要转换的月份数未知,则可以使用类似于以下内容的动态sql:
; with Mth (st, nd) as (
select DATEADD (M, datediff (m, 0,'2012-09-01'), 0),
DATEADD (M, DATEDIFF (m, 0, '2012-09-01') + 1, 0)
union all
select DATEADD (m, 1, st),
DATEADD (m, 1, nd)
from Mth
where nd <= DATEADD (m, datediff (m, 0, getdate()), 0)
)
select *
into #dates
from Mth
DECLARE @cols AS NVARCHAR(MAX),
@query AS NVARCHAR(MAX)
select @cols = STUFF((SELECT ',' + QUOTENAME(month(st))
from #dates
group by month(st)
order by month(st)
FOR XML PATH(''), TYPE
).value('.', 'NVARCHAR(MAX)')
,1,1,'')
set @query = ' with Mth (st, nd) as (
select DATEADD (M, datediff (m, 0,''2012-09-01''), 0),
DATEADD (M, DATEDIFF (m, 0, ''2012-09-01'') + 1, 0)
union all
select DATEADD (m, 1, st),
DATEADD (m, 1, nd)
from Mth
where nd <= DATEADD (m, datediff (m, 0, getdate()), 0)
)
select *
from
(
select MONTH(Mth.st) Month,
COUNT(S.QRY_ID) Searches
FROM Mth
LEFT JOIN SEARCHES S
on Mth.st <= S.CREATED
and Mth.nd > S.CREATED
GROUP BY YEAR(Mth.st), MONTH(Mth.st)
) src
pivot
(
sum(searches)
for month in ('+@cols+')
) piv'
execute(@query)
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.