Useful Article, in sense the author explain a new alternate of GROUP BY for DISTINCT ( Surely Unknown to many ).

For finding the Duplicates, the Query is Okay, but in many situation we are suppose to work on the duplicated data. So instead of Just check the Duplicates, we shall retrieve the total data by the below Query

-- To Check Duplicate Record

SELECT Address1,Address2,City,PostCode,Count(PostCode)

FROM AddressTable

GROUP BY Address1,Address2,City,PostCode

HAVING Count(PostCode) > 1

-- To Retrieve all records identified as Duplicate by some values

SELECT Address1, Address2, City, Postcode

FROM AddressTable a

WHERE (SELECT COUNT(*) FROM AddressTable b

WHERE a.Address1 = b.Address1 and a.Address2 = b.Address2

and a.City = b.City and a.Postcode = b.Postcode

) >1

May be useful to some one.....:-D