For denne type data skal du implementere både UNPIVOT
og derefter PIVOT
funktioner i SQL Server. UNPIVOT
tager dine data fra de flere kolonner og placerer dem i to kolonner, og derefter anvender du PIVOT
at transformere dataene tilbage til kolonner.
Hvis du kender alle de værdier, du vil transformere, så kan du hardkode det, svarende til dette:
select *
from
(
select value, col+'_'+cast(rn as varchar(10)) col
from
(
select nvrchildname,
nvrgender,
convert(varchar(10), dttchildDOB, 120) dttchildDOB,
occupation,
row_number() over(partition by intsid order by intCHID) rn
from tblHRIS_ChildDetails
where intsid = 463
) src
unpivot
(
value
for col in (nvrchildname, nvrgender, dttchildDOB, occupation)
) unpiv
) src1
pivot
(
max(value)
for col in ([nvrchildname_1], [nvrgender_1],
[dttchildDOB_1], [occupation_1],
[nvrchildname_2], [nvrgender_2],
[dttchildDOB_2], [occupation_2])
) piv
Hvis du nu har et ukendt antal værdier at transformere, så kan du bruge dynamisk SQL til dette:
DECLARE @colsUnpivot AS NVARCHAR(MAX),
@query AS NVARCHAR(MAX),
@colsPivot as NVARCHAR(MAX)
select @colsUnpivot = stuff((select ','+quotename(C.name)
from sys.columns as C
where C.object_id = object_id('tblHRIS_ChildDetails') and
C.name not in ('intCHID', 'intsid')
for xml path('')), 1, 1, '')
select @colsPivot = STUFF((SELECT ','
+ quotename(c.name
+'_'+ cast(t.rn as varchar(10)))
from
(
select row_number() over(partition by intsid order by intCHID) rn
from tblHRIS_ChildDetails
) t
cross apply sys.columns as C
where C.object_id = object_id('tblHRIS_ChildDetails') and
C.name not in ('intCHID', 'intsid')
group by c.name, t.rn
order by t.rn
FOR XML PATH(''), TYPE
).value('.', 'NVARCHAR(MAX)')
,1,1,'')
set @query
= 'select *
from
(
select col+''_''+cast(rn as varchar(10)) col, value
from
(
select nvrchildname,
nvrgender,
convert(varchar(10), dttchildDOB, 120) dttchildDOB,
occupation,
row_number() over(partition by intsid order by intCHID) rn
from tblHRIS_ChildDetails
where intsid = 463
) x
unpivot
(
value
for col in ('+ @colsunpivot +')
) u
) x1
pivot
(
max(value)
for col in ('+ @colspivot +')
) p'
exec(@query)
Resultatet af begge forespørgsler er:
| NVRCHILDNAME_1 | NVRGENDER_1 | DTTCHILDDOB_1 | OCCUPATION_1 | NVRCHILDNAME_2 | NVRGENDER_2 | DTTCHILDDOB_2 | OCCUPATION_2 |
-----------------------------------------------------------------------------------------------------------------------------
| SK | Female | 2001-12-11 | Studying | SM | Male | 2007-10-08 | Student |