Showing data as a column name - sql

Question

I have three tables. I called them as Table A,Table B,Table C.
And I have desired view which I want to get.
Table A
Aid RegNum BID Value
2CE7D0A7 2000000 D5981DFC OFFCRO
9D3C13AA 2000000 C58566C5 YCH - from
9DDB90C4 2000000 812E9E75 Y
Table B is connected to Table A by Table B's foreign key in Table A
Table B
BID Label ColumnName Order
D5981DFC Offered/Change Role StatusChangeCode 0
C58566C5 Offered/Role Change Comments StatusChangeComments 1
812E9E75 Assessed StatusChangeAssessed 2
Table C has foreign key in Table A as well. Reg Num. Reg num is primary key in Table C
Table C
Name Surname RegNum
Etibar Hasanov 2000000
As you see there are column's names which are datas in Table B
DesiredView
Name Surname RegNum StatusChangeCode StatusChangeComments StatusChangeAssessed
Etibar Hasanov 2000000 OFFCRO YCH - from Y

Answer 1

You can achieve this by using PIVOT table. Try something like this,
Create Table TableA(Aid varchar(50), RegNum int, BID Varchar(20), Value varchar(50))
insert into TableA values
('2CE7D0A7', 2000000, 'D5981DFC', 'OFFCRO'),
('9D3C13AA', 2000000, 'C58566C5', 'YCH - from' ),
('9DDB90C4', 2000000, '812E9E75', 'Y')
create Table TableB(BID Varchar(20), Label Varchar(50), ColumnName
Varchar(50), [Order] int)
insert into TableB values
('D5981DFC', 'Offered/Change Role', 'StatusChangeCode', 0),
('C58566C5', 'Offered/Role Change Comments', 'StatusChangeComments', 1),
('812E9E75', 'Assessed', 'StatusChangeAssessed', 2)
Create Table TableC (Name Varchar(20), Surname Varchar(20), RegNum int)
insert into TableC values
('Etibar', 'Hasanov', 2000000)
SELECT *
FROM (
SELECT
Name, SurName, C.RegNum, Value, B.ColumnName
FROM TableC C
JOIN TableA A ON C.RegNum = A.RegNum
JOIN TableB B on B.BID = A.BID
) AS Source
PIVOT
(
MAX(Value)
FOR [ColumnName]
in ( [StatusChangeCode], [StatusChangeComments], [StatusChangeAssessed] )
)AS Pvot
Sql Fiddle Demo
If you are using SQL server 2005, according to Microsoft Technet,
When PIVOT and UNPIVOT are used against databases that are upgraded to
SQL Server 2005 or later, the compatibility level of the database must
be set to 90 or higher.

Answer 2

I first selected columns names. In this table it brings [StatusChangeAssessed],[StatusChangeCode],[StatusChangeComments] . Then in the next query I setted #col ( column names ).
declare #nregnumber nvarchar(10)='2000000';
DECLARE #cols AS NVARCHAR(MAX), #runningquery as nvarchar(max);
select #cols = STUFF((SELECT distinct ',' + QUOTENAME(rn)
from
(
select columnname rn from tableb where exists ( select * from tablea where tablea.bid=tableb.bid and regnum=#nregnumber)
) t
FOR XML PATH(''), TYPE
).value('.', 'NVARCHAR(MAX)')
,1,1,'');
set #runningquery='
SELECT *
FROM (
SELECT
Name, SurName, C.RegNum, Value, B.ColumnName
FROM TableC C
JOIN TableA A ON C.RegNum = A.RegNum
JOIN TableB B on B.BID = A.BID
) AS Source
PIVOT
(
MAX(Value)
FOR [ColumnName]
in ( '+#cols+')
)AS Pvot'
exec (#runningquery)
Special thanks to Selva.