Pivot multiple columns based on one column in SQL Server
Since you are using SQL Server there are several different ways that you can convert the rows into columns. You can use an aggregate function with a CASE expression:
select empid,
max(case when empindex = 1 then empstate end) empState1,
max(case when empindex = 1 then empStDate end) empStDate1,
max(case when empindex = 1 then empEndDate end) empEndDate1,
max(case when empindex = 2 then empstate end) empState2,
max(case when empindex = 2 then empStDate end) empStDate2,
max(case when empindex = 2 then empEndDate end) empEndDate2
from sourcetbl
group by empid;
See SQL Fiddle with Demo.
If you want to use the PIVOT function to get the result, then I would recommend first unpivoting the columns empState
, empStDate
and empEndDate
so you will have multiple rows first. You can use the UNPIVOT function or CROSS APPLY to convert the data the code will be:
select empid, col+cast(empindex as varchar(10)) col, value
from sourcetbl
cross apply
(
select 'empstate', empstate union all
select 'empstdate', convert(varchar(10), empstdate, 120) union all
select 'empenddate', convert(varchar(10), empenddate, 120)
) c (col, value);
See Demo. Once the data is unpivoted, then you can apply the PIVOT function so the final code will be:
select empid,
empState1, empStDate1, empEndDate1,
empState2, empStDate2, empEndDate2
from
(
select empid, col+cast(empindex as varchar(10)) col, value
from sourcetbl
cross apply
(
select 'empstate', empstate union all
select 'empstdate', convert(varchar(10), empstdate, 120) union all
select 'empenddate', convert(varchar(10), empenddate, 120)
) c (col, value)
) d
pivot
(
max(value)
for col in (empState1, empStDate1, empEndDate1,
empState2, empStDate2, empEndDate2)
) piv;
See SQL Fiddle with Demo.
Th above versions will work great if you have a limited number of empindex
, but if not then you can use dynamic SQL:
DECLARE @cols AS NVARCHAR(MAX),
@query AS NVARCHAR(MAX)
select @cols = STUFF((SELECT ',' + QUOTENAME(col+cast(empindex as varchar(10)))
from SourceTbl
cross apply
(
select 'empstate', 1 union all
select 'empstdate', 2 union all
select 'empenddate', 3
) c (col, so)
group by col, so, empindex
order by empindex, so
FOR XML PATH(''), TYPE
).value('.', 'NVARCHAR(MAX)')
,1,1,'')
set @query = 'SELECT empid,' + @cols + '
from
(
select empid, col+cast(empindex as varchar(10)) col, value
from sourcetbl
cross apply
(
select ''empstate'', empstate union all
select ''empstdate'', convert(varchar(10), empstdate, 120) union all
select ''empenddate'', convert(varchar(10), empenddate, 120)
) c (col, value)
) x
pivot
(
max(value)
for col in (' + @cols + ')
) p '
execute sp_executesql @query;
See SQL Fiddle with Demo
You can use these queries to INSERT INTO your DestTbl
, or instead of storing the data in this format, you now have a query to get the desired result.
These queries place the data in the format:
| EMPID | EMPSTATE1 | EMPSTDATE1 | EMPENDDATE1 | EMPSTATE2 | EMPSTDATE2 | EMPENDDATE2 |
---------------------------------------------------------------------------------------
| 10 | AL | 2012-01-01 | 2012-12-01 | FL | 2012-02-01 | 2013-02-01 |
| 15 | FL | 2012-03-20 | 2099-01-01 | (null) | (null) | (null) |