IF EXISTS (SELECT 1 FROM sys.foreign_keys WHERE object_id = OBJECT_ID(N'[dbo].[FK_InvoicedItem_PurchaseOrderDetail]', 'F')
    AND parent_object_id = OBJECT_ID(N'[dbo].[InvoicedItem]', 'U')
    AND OBJECT_ID('[dbo].[PurchaseOrderDetail].[InvoicedItemIDTemp]') <> NULL) --I added this recently, just in case
BEGIN
    --Even if that condition evaluates to false, I'm seeing an error about PurchaseOrderDetail.InvoicedItemIDTemp not existing... which it wouldn't, if that evaluated to false.  What gives?
    UPDATE pp
    SET pp.InvoicedItemIDTemp = (SELECT InvoicedItemID FROM InvoicedItem ii WHERE ii.PurchaseOrderDetailID = pp.PurchaseOrderDetailID AND ii.Active=1) FROM PurchaseOrderDetail pp
END
GO