Here's what I did
Month1:
Insert into Bulkcopy(CompanyName ,CompanyNumber ,
AddressLine,PostTown,Country,PostCode,CompanyStatus)
('A Company','006','2 Main st','White Plains','NY','USA',null,'1')
Staging Month1:
Select CompanyName +','+CompanyNumber +','+
AddressLine+','+PostTown+','+Country+','+PostCode+','+CompanyStatus+','+CheckSumval
from Staging;
will yield
A Company,006,2 Main st,White Plains,NY,USA,null,1,123456
Master Month1:
--delta
insert into Master(CompanyName ,CompanyNumber ,
AddressLine,PostTown,Country,PostCode,CompanyStatus,CheckSumval,lastupdated)
select top 10 stg.CompanyName,...