Eu fiz muitas dessas consultas dinâmicas ultimamente... (minhas colunas mudam por cliente por mês). Aqui está uma maneira de fazer isso - sem testes, sem depuração, pode haver alguns bugs para resolver:
DECLARE
@Command nvarchar(max)
,@ColumnList nvarchar(max)
,@OrderId int
,@Debug bit
-- Build a comman-delimited list of the columns
SELECT @ColumnList = isnull(@ColumnLIst + ',', , '') + ColName
from dbo.GetTableColumnNames('OrderCash', 2)
-- Insert the list of columns in two places in your query
SET @Command = replace('
SELECT OrderID,
CurrCode + ‘‘GBP CURNCY’‘ AS Ticker,
Cash AS Position
FROM
(
SELECT OrderID, <@ColumnList>
FROM OrderCash
) p
UNPIVOT
(
Cash FOR CurrCode IN
(<@ColumnList>)
) AS unpvt
WHERE Cash != 0
And OrderID = @OrderId
', '<@ColumnList>', @ColumnList)
-- Always include something like this!
IF @Debug = 1
PRINT @Command
-- Using sp_executeSQL over EXECUTE (@Command) allows you execution
-- plan resuse with parameter passing (this is the part you may need
-- to debug on a bit, but it will work)
EXECUTE sp_executeSQL @Command, N'@OrderId int', @OrderId
