-- =============================================
-- Author:		<Author,,Name>
-- Create date: <Create Date, ,>
-- Description:	<Description, ,>
-- =============================================
CREATE FUNCTION [dbo].[fds__fn_IntermediateIsAllocatedToOther]
(
	@Intermediate_InvID varchar(10)
	,@Target_InvID varchar(10)

)
RETURNS bit
AS
BEGIN
	-- An allocation only counts while the crediting invoice is alive: once that invoice is cancelled
	-- (storno) its credit line is void and the Abschlagsrechnung must be offered again (ADR 0034).
	DECLARE @IsA bit = CASE WHEN EXISTS (SELECT 1 FROM [dbo].[fds__invoices] as intermediates JOIN [dbo].[fds__invoice_details] as id on intermediates.[Id] = id.[InvId] and id.[AllocatedTo_InvId] is not null
														JOIN [dbo].[fds__invoices] as non_intermediates ON id.[AllocatedTo_InvId] = non_intermediates.[Id] and id.[AllocatedTo_InvId] is not null
													WHERE intermediates.[Id] = @Intermediate_InvID
														and ISNULL(non_intermediates.[IsCanceled], 0) = 0
														and (@Target_InvID is null or non_intermediates.[Id] <> @Target_InvID))
									THEN 1 ELSE 0 END;

	RETURN @isA;

END