Eliminating duplicate data in just one column

  • I have a query which returns duplicate date in 1 column as such (c1 = Column 1; c2 = Column 2)

    TABLE

    c1 | c2

    A | X

    A | Y

    B | Z

    I need to rewrite the query so it returns the following:

    A | X

    B | Z

    OR

    A | Y

    B | Z

    The goal is to eliminate the duplicate data in C1. So if it was

    B | X

    B | Y

    A | Z

    The goal would be for the query to return

    B | X

    A | Z

    OR

    B | Y

    A | Z

    Also, duplicate data does not exist in c2

    Is the following the correct query to write this? (I do not have SQL 2K5 at my house to run this)

    SELECT TOP 1 c1, c2

    FROM table

    WHERE COUNT(c1) > 1

    UNION ALL

    SELECT c1, c2

    FROM table

    WHERE COUNT(c1) = 1

    the 1st half of the UNION ALL statement would return just: (I'm doing this in my head)

    A | X

    because only the first row of # rows returned (A being in c1 more than 1)

    While the 2nd half of the UNION ALL statement would return because B satisfies COUNT(c1) = 1

    B | Z

    Could someone comment if I'm doing this correctly or if there is a way of doing it better?

    I appreciate your help!

  • try this:

    ; with numbered_dupes_cte as

    (

    select rn = row_Number() over (partition by c1, c2),

    c1, c2

    from table

    )

    select * from numbered_dupes_cte where rn = 1

  • Is it possible to translate this into Access 2003 DB could interpret?

    Once again, I appreciate your response. My code apparently does not take

  • umanpowered (9/26/2010)


    ...

    The goal is to eliminate the duplicate data in C1. So if it was

    B | X

    B | Y

    A | Z

    The goal would be for the query to return

    B | X

    A | Z

    OR

    B | Y

    A | Z

    ...

    To get

    B | X

    A | Z

    try:

    Select C1, MIN(C2) AS C2

    From [Table]

    Group By C1

    To get

    B | Y

    A | Z

    you an use:

    Select C1, MAX(C2) AS C2

    From [Table]

    Group By C1

    _____________________________________________
    "The only true wisdom is in knowing you know nothing"
    "O skol'ko nam otkrytiy chudnyh prevnosit microsofta duh!":-D
    (So many miracle inventions provided by MS to us...)

    How to post your question to get the best and quick help[/url]

  • Euguene, IT WORKS! I appreciate your help. I didn't think about the MIN function. 🙂

  • Happy to Help!

    _____________________________________________
    "The only true wisdom is in knowing you know nothing"
    "O skol'ko nam otkrytiy chudnyh prevnosit microsofta duh!":-D
    (So many miracle inventions provided by MS to us...)

    How to post your question to get the best and quick help[/url]

Viewing 6 posts - 1 through 5 (of 5 total)

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