The script below illustrates how to compare two tables that are identical in order to verify if the values are really the same in both tables:
USE NORTHWIND
GO
SELECT *
INTO dbo.shippers_test
FROM dbo.shippers
UPDATE dbo.shippers_test
SET companyname = ‘Speedy’
WHERE shipperid = 1
UPDATE dbo.shippers
SET companyname = ‘Feral Shipping’
WHERE shipperid = 3
SELECT *
FROM dbo.shippers T1 FULL OUTER JOIN dbo.shippers_test T2
ON T1.shipperid = T2.shipperid
AND T1.companyname = T2.companyname
WHERE T1.shipperid IS NULL
OR T2.shipperid IS NULL