SQL Server : rows into columns - sql-server-2008

Question

I have three tables. I need to swith row values into columns.
Table-1: [Approval_Type]
App_ID Type_Ds
2 RMC2
1 RMC1
Table 2: [Project]
Pro_id Summary
1 PROJECT1
2 PROJECT2
Table:3 [Prj_App]
App_Id Pro_Id ExpDt ComDt
1 2 2010-06-05 2010-07-06
1 1 1999-05-05 1999-05-06
2 1 1900-01-01 1900-01-05
I want to display my result as
Pro_Id RMC2 RMC2ExpeDt RMC2ComDt RMC1 RMC1ExpeDt RMC1ComDt
1 RMC2 1900-01-01 1900-01-05 RMC1 1999-05-05 1999-05-06
2 NULL NULL NULL RMC1 2010-06-05 2010-07-06
Below is my query which returns'
DECLARE #SQL1 NVARCHAR(MAX) = ''
DECLARE #SQL NVARCHAR(MAX) = ''
SELECT #SQL1 = STUFF((SELECT ',' + QUOTENAME(Type_Ds) + ',' + QUOTENAME(Type_Ds + ' Expected Date') + ',' + QUOTENAME(Type_Ds + ' Completed Date')
from dbo.AppType
FOR XML PATH(''), TYPE
).value('.', 'NVARCHAR(MAX)')
,1,1,'')
print #SQL1
SET #SQL = 'SELECT *
FROM ( SELECT A.Pro_Id,
Type_DS
FROM dbo.Project A left join [dbo].[Prj_App] B on A.Pro_id = B.Pro_Id
right outer join dbo.AppType C on B.App_Id = C.App_ID
) data
PIVOT
( MAX(Type_DS)
FOR Type_DS IN (' + #SQL1 + ')
) pvt1
where Pro_Id is not null'
print #SQL
EXECUTE SP_EXECUTESQL #SQL
Pro_Id RMC2 RMC2ExpeDt RMC2ComDt RMC1 RMC1ExpeDt RMC1ComDt
1 RMC2 NULL NULL RMC1 NULL NULL
2 NULL NULL NULL RMC1 NULL NULL.
can anyone help on it...

Answer 1

My suggestion when you are working with dynamic SQL is to always write the query hard-coded first, so you can get the logic correct, then convert it to dynamic SQL.
Since you are attempting to pivot 3 columns of data I would first unpivot the type_ds, expdt and comdt` columns, then apply the PIVOT function.
The hard-coded version of the query will be:
SELECT *
FROM
(
select pro_id,
type_ds = case
when col ='type_ds'
then type_ds
else type_ds+col end,
value
from
(
SELECT A.Pro_Id,
c.Type_DS,
convert(varchar(10), b.ExpDt, 120) ExpDt,
convert(varchar(10), b.ComDt, 120) ComDt
FROM dbo.Project A
left join [dbo].[Prj_App] B
on A.Pro_id = B.Pro_Id
right outer join dbo.Approval_Type C
on B.App_Id = C.App_ID
) s
cross apply
(
select 'type_ds', type_ds union all
select 'expdt', expdt union all
select 'comdt', comdt
) c (col, value)
) data
PIVOT
(
MAX(value)
FOR Type_DS IN (RMC2, RMC2expdt, RMC2comdt,
RMC1, RMC1expdt, RMC1comdt)
) pvt1
See SQL Fiddle with Demo. Now that you have a working version of the query, you can easily convert it to dynamic SQL:
DECLARE #SQL1 NVARCHAR(MAX) = ''
DECLARE #SQL NVARCHAR(MAX) = ''
SELECT #SQL1 = STUFF((SELECT ',' + QUOTENAME(Type_Ds) + ',' + QUOTENAME(Type_Ds + 'ExpDt') + ',' + QUOTENAME(Type_Ds + 'ComDt')
from dbo.Approval_Type
FOR XML PATH(''), TYPE
).value('.', 'NVARCHAR(MAX)')
,1,1,'')
SET #SQL = 'SELECT *
FROM
(
select pro_id,
type_ds = case
when col =''type_ds''
then type_ds
else type_ds+col end,
value
from
(
SELECT A.Pro_Id,
c.Type_DS,
convert(varchar(10), b.ExpDt, 120) ExpDt,
convert(varchar(10), b.ComDt, 120) ComDt
FROM dbo.Project A
left join [dbo].[Prj_App] B
on A.Pro_id = B.Pro_Id
right outer join dbo.Approval_Type C
on B.App_Id = C.App_ID
) s
cross apply
(
select ''type_ds'', type_ds union all
select ''expdt'', expdt union all
select ''comdt'', comdt
) c (col, value)
) data
PIVOT
(
MAX(value)
FOR Type_DS IN (' + #SQL1 + ')
) pvt1 '
--print #SQL
EXECUTE SP_EXECUTESQL #SQL
See SQL Fiddle with Demo