Deleting Duplicate Rows

  • Comments posted to this topic are about the content posted at http://www.sqlservercentral.com/columnists/darjun/deletingduplicaterows.asp

    Deepak Arjun
    Mobile (+91) 09885088054

  • why not just Union the table with itself?

  • Thanks for that, seems less hassle to do it this way.

  • In this particular case, you could do:

    select distinct *

    from OrderDetail

    The problem with removing duplicates is that there are so many variations that no one solution fixes all. You just need to be aware of different ways of achieving the same result.

    Jeremy

  • Mr deepak can have a look into

    http://www.sqlteam.com/forums/topic.asp?TOPIC_ID=6256

  • Thanks for all the comments on this article. Ofcourse there are lots of ways to delete multiple records and this method is only one of the approaches.

    But every methods used depends on table size, no of columns and ease of convenience. For this method,You need not write cursors, tricky queries.It is fast bcos it uses bulk copy operation and it holds true for every table with duplicate rows with any number of duplicate columns.

    quote:


    Mr deepak can have a look into

    http://www.sqlteam.com/forums/topic.asp?TOPIC_ID=6256


    Deepak Arjun
    Mobile (+91) 09885088054

  • Mr deepak good work .might be other ways to do the process.but this way is simple and its userfriendly isnt.

  • The query will be composed this way:-

    WITH TempUsers (FirstName,LastName, duplicateRecordCount)

    AS

    (

    SELECT FirstName,LastName,

    ROW_NUMBER()OVER(PARTITIONBY FirstName, LastName ORDERBY FirstName) AS duplicateRecordCount

    FROM dbo.Users

    )

    DELETE

    FROM TempUsers

    WHERE duplicateRecordCount > 1

    GO

    Instead of TempUsers you can give any name. Because this is used only for Temporary purpose.

    Cheers,
    Bijayani
    Proud to be a part of Team Mindfire.

    Mindfire[/url]: India's Only Company to be both Apple Premier & Microsoft Gold certified.

Viewing 8 posts - 1 through 7 (of 7 total)

You must be logged in to reply to this topic. Login to reply