CREATE VIEW dbo.uvw_StockingDays
AS
SELECT ItemNmbr
     , ItemDesc
     , dbo.ufn_SplitGet(USCATVLS_1, '-', 1) AS MinDays -- custom function that splits the text on '-' and returns the first index
     , dbo.ufn_SplitGet(USCATVLS_1, '-', 2) AS MaxDays
FROM IV00101
GO

CREATE TRIGGER dbo.upd_StockingDays
ON uvw_StockingDays
INSTEAD OF UPDATE AS
IF (COLUMNS_UPDATED() & 12) > 0 -- the last two columns
    UPDATE IV00101
    SET USCATVLS_1 = MinDays + '-' + MaxDays -- invalid column names
    WHERE IV00101.ItemNmbr = ItemNmbr -- want to refer to view's itemnmbr
GO