Question

I have 2 tables with the same schema, one is just a table that data gets bulk loaded into and the other is my live table. I want to update the live table from the uploaded table where the rows are different. I think I am pretty close here but where would my UPDATE actually come into play?

This gives me my updated rows that actually have changes I want to push into my live table:

SELECT USC.* FROM UpdateStagingCustomers AS USC
JOIN StagingCustomers AS SC
ON USC.CustomerNumber = SC.CustomerNumber
AND USC.ManufacturerID = SC.ManufacturerID
WHERE USC.ManufacturerID=18 AND SC.ManufacturerID = 18
    AND USC.CustomerNumber IN(
        SELECT CustomerNumber FROM StagingCustomers WHERE ManufacturerID=18
    )
    AND 
    (
    USC.Address1 <> SC.Address1 OR
    USC.Address2 <> SC.Address2 OR
    USC.AuthorizedDealer <> SC.AuthorizedDealer OR
    USC.City <> SC.City
    )

Answer 1

I believe this SQL Statement will do the job, but you might want to test it in a rolled back transaction.

UPDATE StagingCustomers 
SET Address1 = USC.Address1, 
    Address2 = USC.Address2, 
    AuthorizedDealer = USC.AuthorizedDealer,
    City = USC.City
FROM UpdateStagingCustomers AS USC
JOIN StagingCustomers AS SC
ON USC.CustomerNumber = SC.CustomerNumber
AND USC.ManufacturerID = SC.ManufacturerID
WHERE USC.ManufacturerID=18 AND SC.ManufacturerID = 18
    AND USC.CustomerNumber IN(
        SELECT CustomerNumber FROM StagingCustomers WHERE ManufacturerID=18
    )
    AND 
    (
    USC.Address1 <> SC.Address1 OR
    USC.Address2 <> SC.Address2 OR
    USC.AuthorizedDealer <> SC.AuthorizedDealer OR
    USC.City <> SC.City
    )