Data in one column contains column name of other table

I have one table in one of its column it stored column name of another
table. i want select statement to select that column name. i will explain
this with example
Table1 has columns with name ID,col1 and having data in that column as
(1,tb_col1),(2,tb_col2),(3,tb_col3) etc
and another table has this columndata of table one as column name means
table2 has column (tab_id2,tb_col1,tb_col2,tb_col3)
inthis if i select ID=1 from table1 then select statement should show me
data in column tb_col1 of table2..
if i select ID=2 from table1 then select statement should show me data in
column tb_col2 of table2..
here data in column col1 of table1 may change any time so i want it
dynamically
Message posted via http://www.webservertalk.comYou need to use dynamic sql.
Example:
create procedure dbo.proc1
@.id int
as
set nocount on
declare @.sql nvarchar(4000)
if exists(select * from table1 where [id] = @.id)
begin
set @.sql = N'select [' + (select top 1 col1 from table1 where [id] =
@.id) + N'] from table2'
exec sp_executesql @.sql
end
return @.@.error
go
exec dbo.proc1 1
exec dbo.proc1 2
go
The Curse and Blessings of Dynamic SQL
http://www.sommarskog.se/dynamic_sql.html
AMB
"Malkesh Sheth via webservertalk.com" wrote:

> I have one table in one of its column it stored column name of another
> table. i want select statement to select that column name. i will explain
> this with example
> Table1 has columns with name ID,col1 and having data in that column as
> (1,tb_col1),(2,tb_col2),(3,tb_col3) etc
> and another table has this columndata of table one as column name means
> table2 has column (tab_id2,tb_col1,tb_col2,tb_col3)
> inthis if i select ID=1 from table1 then select statement should show me
> data in column tb_col1 of table2..
> if i select ID=2 from table1 then select statement should show me data in
> column tb_col2 of table2..
> here data in column col1 of table1 may change any time so i want it
> dynamically
> --
> Message posted via http://www.webservertalk.com
>|||>> I have one table in one of its column it stored column name of
another table. <<
This is called mixing data and metadata. Good SQL programmers do not
write code like this! Bad SQL programmers use Dynamic SQL and lose
their data integrity.