问题
I have a database in which I have the following rows:
ID | Date start | Date end
----------------------------------
a | 01-01-1950 | 30-01-1951
a | 01-01-1948 | 31-12-1949
a | 31-01-1951 | 01-06-2000
b | 01-01-1980 | 01-08-2010
c | 01-01-1990 | 31-12-2017
c | 31-01-1985 | 31-12-1989
What I got
- Multiple rows per person
- One start and end date per row
- In a not chronological order
Select query which I want to return the following:
ID | Date start 1 | Date end 1 | Date start 2 | Date end 2 | Date start 3 | Date end 3
---------------------------------------------------------------------------------------------------
a | 01-01-1948 | 31-12-1949 | 01-01-1950 | 30-01-1951 | 31-01-1951 | 01-06-2000
b | 01-01-1980 | 01-08-2010
c | 31-01-1985 | 31-12-1989 | 01-01-1990 | 31-12-2017
What I want:
- One row per person
- Multiple start and end dates per row
- In a chronological order
Most things I was able to find wanted it in the same column, or wouldn't want it sorted on chronological order, so unfortunately those situations didn't apply to me.
I really have now clue how to solve this.
回答1:
If you have only three dates, then pivot/conditional aggregation should be fine:
select id,
max(case when seqnum = 1 then dstart end) as start_1,
max(case when seqnum = 1 then dend end) as end_1,
max(case when seqnum = 2 then dstart end) as start_2,
max(case when seqnum = 2 then dend end) as end_2,
max(case when seqnum = 3 then dstart end) as start_3,
max(case when seqnum = 3 then dend end) as end_3
from (select t.*,
row_number() over (partition by id order by dstart) as seqnum
from t
) t
group by id;
Note: You have to specify the number of columns in the output. If you don't know how many there are, you can either:
- Generate a dynamic SQL statement to do the count in advance.
- Manually count yourself and add the appropriate columns.
回答2:
Gordon's conditional aggregation would be my first choice. However, If you need to go DYNAMIC
Declare @SQL varchar(max) = Stuff((Select Distinct ',' + QuoteName(concat('Date Start ',RN)) +',' + QuoteName(concat('Date End ',RN))
From (Select Distinct RN=Row_Number() over (Partition By ID Order By [Date Start])
From YourTable) A
Order by 1 For XML Path('')),1,1,'')
Select @SQL = '
Select [ID],' + @SQL + '
From (
Select ID,B.*
From (
Select *,RN=Row_Number() over (Partition By ID Order By [Date Start]) From YourTable
) A
Cross Apply (Values (concat(''Date Start '',A.RN),A.[Date Start])
,(concat(''Date End '',A.RN),A.[Date End]) ) B (Col,Value)
) A
Pivot (max(Value) For [Col] in (' + @SQL + ') ) p'
Exec(@SQL);
Returns
回答3:
Assuming you have a static number of date-ranges, you could achieve this using a window function as follows...
;WITH cteData
(
ID,
DateStart,
DateEnd
)
AS
(
SELECT 'a', CONVERT(DATE, '01-01-1950'), CONVERT(DATE, '30-01-1951')
UNION ALL SELECT 'a', '01-01-1948', '31-12-1949'
UNION ALL SELECT 'a', '31-01-1951', '01-06-2000'
UNION ALL SELECT 'b', '01-01-1980', '01-08-2010'
UNION ALL SELECT 'c', '01-01-1990', '31-12-2017'
UNION ALL SELECT 'c', '31-01-1985', '31-12-1989'
),
cteDefineColumns
AS
(
SELECT RangeColumnID = ROW_NUMBER() OVER (PARTITION BY ID ORDER BY DateStart),
*
FROM cteData
)
SELECT col1.ID,
[Date start 1] = col1.DateStart,
[Date end 1] = col1.DateEnd,
[Date start 2] = col2.DateStart,
[Date end 2] = col2.DateEnd,
[Date start 3] = col3.DateStart,
[Date end 3] = col3.DateEnd
FROM cteDefineColumns AS col1
LEFT OUTER JOIN cteDefineColumns AS col2
ON col1.ID = col2.ID
AND col2.RangeColumnID = 2
LEFT OUTER JOIN cteDefineColumns AS col3
ON col1.ID = col3.ID
AND col3.RangeColumnID = 3
WHERE col1.RangeColumnID = 1
ORDER BY col1.ID,
col1.DateStart,
col1.DateEnd;
回答4:
I'm not sure why do you neet it, because this structure is not too good.
if object_Id('tempdb..#TmpRankedTable') is not null drop table #TmpRankedTable
select Id, strt_dt, end_dt, row_number() over(partition by Id order by strt_dt) OrbyCol
into #TmpRankedTable
from dbo.YourTable
if object_Id('tempdb..#TmpStarts') is not null drop table #TmpStarts
select *
into #TmpStarts
from (
select Id, strt_dt, OrbyCol
from #TmpRankedTable) t
pivot (min(strt_dt) for OrbyCol in ([1],[2],[3],[4],[5],[6],[7],[8],[9],[10])) p
if object_Id('tempdb..#TmpEnds') is not null drop table #TmpEnds
select *
into #TmpEnds
from (
select Id, end_dt, OrbyCol
from #TmpRankedTable) t
pivot (min(end_dt) for OrbyCol in ([1],[2],[3],[4],[5],[6],[7],[8],[9],[10])) p
select
s.Id,
s.[1] [Start 1],
e.[1] [End 1],
s.[2] [Start 2],
e.[2] [End 2],
s.[3] [Start 3],
e.[3] [End 3],
s.[4] [Start 4],
e.[4] [End 4],
s.[5] [Start 5],
e.[5] [End 5],
s.[6] [Start 6],
e.[6] [End 6],
s.[7] [Start 7],
e.[7] [End 7],
s.[8] [Start 8],
e.[8] [End 8],
s.[9] [Start 9],
e.[9] [End 9],
s.[10] [Start 10],
e.[10] [End 10]
from #TmpStarts s
inner join #TmpEnds e on s.Id = e.Id
回答5:
You can use pivot to transpose and query as below:
;with cte as (
select *, RowN = row_number() over(partition by id order by datestart) from #temp )
, cte2 as (
select id, [1] as [datestart1], [2] as [datestart2], [3] as datestart3 from
(select id, datestart, RowN from cte) sourcetable
pivot (max(datestart) for RowN in ([1],[2],[3]) ) p
)
, cte3 as (
select id, [1] as [dateend1], [2] as [dateend2], [3] as dateend3 from
(select id, dateend, RowN from cte) sourcetable
pivot (max(dateend) for RowN in ([1],[2],[3]) ) p
) select c2.id, c2.datestart1,c3.dateend1,c2.datestart2,c3.dateend2,c2.datestart3,c3.dateend3
from cte2 c2 left join cte3 c3 on c2.id = c3.id
If you have dynamic columns you can create dynamic query using stuff to create list of columns and run this query as dynamic query to get all list of columns
来源：https://stackoverflow.com/questions/41465261/sql-server-combine-multiple-rows-to-one-row-with-multiple-columns