[Microsoft][SQL Server Native Client 10.0][SQL Server]Cannot insert the value NULL into column 'ItmsGrpCod',

hi all

we want to edit item group code in SAP B1

we are getting error:-

([Microsoft][SQL Server Native Client 10.0][SQL Server]Cannot insert the value NULL into column 'ItmsGrpCod', table 'NPL_N03_Test_04Jan2015.dbo.AITB'; column does not allow nulls. INSERT fails. '' (AITB))

please guide further

thanks

yasmeen