Question

How can I use a variable as db context?

Create Procedure [dbo].[prName] (@dbname varchar(25)) as
begin
use master
some sql
<!--  I need to use master for some functions stored in master -->


use @dbname

exec('SELECT column_name FROM INFORMATION_SCHEMA.COLUMNS WHERE [TABLE_CATALOG] = '+@dbname+' and TABLE_NAME=table123')

end

GO

Thanks

Answer 1

I think you might want to use the following:

CREATE Procedure [dbo].[prName] (@dbname varchar(25)) as
begin
   exec('select top 5 * from '+@dbname+'.yourSchema.yourTable')
end

The USE statement is not allowed in a stored procedure. If you are passing in the database name, then you do not need the USE statement, the database name will be included in your sql query.

Edit: Based on your edit that you need to access items in master, then all you need to do is execute your sql, specifying the need of master just use fully qualified sql.

CREATE Procedure [dbo].[prName] (@dbname varchar(25)) as
begin

    select * from master.INFORMATION_SCHEMA.TABLES

    exec('select top 5 * from '+@dbname+'.yourSchema.yourTable')
end