Question

Possible Duplicate:
How Do You Delete Duplicate Records In SQL

I have a table with columns:

FirstName
LastName
AddressLine1
AddressLine2
City
State

For each row, AddressLine1 is different from AddressLine2 value. But there are some duplicates rows, in which AddressLine1 of some records matches with AddressLine2 of some other record.

I want to get rid of such records mentioned above.

Answer 1

This will get all duplicate records:

SELECT P.*
FROM table P INNER JOIN
     table S ON P.FirstName = S.FirstName
            AND P.LastName = S.LastName
WHERE P.AddressLine1 = S.AddressLine2

If your table had an ID you could write a delete to remove duplicates like this:

DELETE FROM table
WHERE Id IN (
  SELECT P.Id
  FROM table P INNER JOIN
       table S ON P.FirstName = S.FirstName
              AND P.LastName = S.LastName
  WHERE P.AddressLine1 = S.AddressLine2
)