UFN_RECURRINGGIFTINSTALLMENTWRITEOFF_PAYMENTHANDLINGVALID

create function dbo.UFN_RECURRINGGIFTINSTALLMENTWRITEOFF_PAYMENTHANDLINGVALID(
  @RECURRINGGIFTINSTALLMENTID uniqueidentifier,
  @WRITEOFFID uniqueidentifier
)
returns bit
with execute as caller
as begin
  declare @PAYMENTID uniqueidentifier;

  select @PAYMENTID = PAYMENTID
  from dbo.RECURRINGGIFTWRITEOFF
  where ID = @WRITEOFFID
  and REASONTYPECODE = 1;

  if @PAYMENTID is not null
  begin
    if exists(select 'x'
              from dbo.RECURRINGGIFTWRITEOFF w
              inner join dbo.RECURRINGGIFTINSTALLMENTWRITEOFF iw on iw.WRITEOFFID = w.ID
              where w.PAYMENTID = @PAYMENTID
              and iw.RECURRINGGIFTINSTALLMENTID = @RECURRINGGIFTINSTALLMENTID
              and w.ID <> @WRITEOFFID)
      return 0;
  end

  return 1;
end