delete from duplicate records

  • i am finding duplicates like this

    SELECT     ChstoragelocationCode

    FROM         StorageLocation

    GROUP BY ChstoragelocationCode

    HAVING      COUNT(ChstoragelocationCode) > 1

    order by ChstoragelocationCode

    now i want to delete all duplicates of particular record and want to keep only one form that duplicate records

    suppose for "ChstoragelocationCode" i am getting 4 records so i want only one out of 4

    Plz suggest

  • If you have an identity field or some unqiue integer field like StorageLocationID - unique id .... the below will work

    drop table #StorageLocation

    go

    create table #StorageLocation ( StorageLocationID int identity(1,1) , ChstoragelocationCode varchar(30))

    go

    insert #StorageLocation select 'SBC'

    insert #StorageLocation select 'SBC'

    insert #StorageLocation select 'SBC'

    go

    SELECT * FROM #StorageLocation

    go

    DELETE sto

    FROM   #StorageLocation sto

    WHERE EXISTS ( SELECT *

                   FROM   #StorageLocation

                   WHERE  ChstoragelocationCode = sto.ChstoragelocationCode

                   AND    StorageLocationID > sto.StorageLocationID)

    go

    SELECT * FROM #StorageLocation

    go

     

  • The following articles will tell you how to do it

    http://www.sqlteam.com/item.asp?ItemID=3331

    http://www.sql-server-performance.com/rd_delete_duplicates.asp

    There is also an article on technet about how to do this

    Dave

  • Thought AH did a pretty good job!

    --Jeff Moden


    RBAR is pronounced "ree-bar" and is a "Modenism" for Row-By-Agonizing-Row.
    First step towards the paradigm shift of writing Set Based code:
    ________Stop thinking about what you want to do to a ROW... think, instead, of what you want to do to a COLUMN.
    "Change is inevitable... change for the better is not".

    Helpful Links:
    How to post code problems
    How to Post Performance Problems
    Create a Tally Function (fnTally)
    Intro to Tally Tables and Functions

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