Stored procedure in purchase order for duplicate item for a vendor

Question

Hi all
I have written a stored procedure for duplicate item for vendor the output i need from this SP is whenever for a vendor we will raise purchase order the system should check that their shouldn't be any po in the system for the same item by the selected vendor. Its working fine when only one item is selected but it is behaving wrongly when more than one item is selected.
If (@object_type='22' and @transaction_type='A')
BEGIN
Declare @Vend as varchar(200)
Declare @ItemCode as varchar(200)
Select @Vend =CardCode From OPOR Where DocEntry = @list_of_cols_val_tab_del
Select @ItemCode=ItemCode From POR1 Where DocEntry=@list_of_cols_val_tab_del
IF 1 !=(Select Count(T0.DocEntry) From OPOR T0  Inner Join POR1 T1 On T0.DocEntry=T1.DocEntry  Where T0.CardCode=@Vend and T1.ItemCode=@ItemCode)
Begin
select @error =1
select @error_message = 'Item Code Already Exists For This Vendor'
end
end
Thanks
Rashid.

Answer 1

Hi Rashid,
Try this,
if @object_type = N'22' and @transaction_type in (N'A', N'U')
begin
declare @line1 int
declare @lin1 int
declare @out1 int
Set @out1 = 0
SET @lin1 = 0
Declare @Vend as varchar(200)
Declare @ItemCode as varchar(200)
Select @Vend = CardCode From OPOR Where DocEntry = @list_of_cols_val_tab_del
Select @line1 = Max (LineNum)FROM POR1 WHERE POR1.DocEntry = @list_of_cols_val_tab_del
While @lin1 < @line1
Begin
     Select @ItemCode=ItemCode From POR1 Where DocEntry=@list_of_cols_val_tab_del and LineNum = @lin1
      if (SELECT COUNT(T0.DocEntry) FROM POR1 T0 inner join OPOR T1 on T0.DocEntry = T1.DocEntry
      WHERE T0.ItemCode = @ItemCode and T1.CardCode = @Vend)> 1
      Begin
           Set @Out1 = 1
           Break;
      END
           Else
           Begin
           Set @lin1 = @lin1+1
           Continue
      END
END
Set @lin1 = @lin1 + 1
if @out1 = 1
begin
      Set @error = 1
      Set @error_message = 'Item Code in line ' + CONVERT(nvarchar(4), @lin1) + N'already Exists For This Vendor!'
End
END
Regards,
Bala