Re: Skill testing SQL question

From: Marc Weinsock <MWeinstock_at_lds.com>
Date: Thu, 04 Nov 1999 21:47:39 GMT
Message-ID: <3821FE23.556D1A7E@lds.com>

How about:
delete from DUPE_TABLE a
where a.rowid > (select min(b.rowid) from DUPE_TABLE b

                            where b.AA = a.AA
                              and b.BB = a.BB )

argosy22_at_my-deja.com wrote:

> Hello all,
>
> This is a good skill testing question
> that I was asked in an interview.
>
> You have a table, DUPE_TABLE,
> with two fields, AA, and BB.
> No primary key. Dupe data.
> Only 6 rows.
> 2 sets of the same exact 3 rows.
>
> DUPE_TABLE:
> AA BB
> 1 x
> 2 y
> 3 z
> 1 x
> 2 y
> 3 z
>
> You want to delete 3 rows, so that
> you have only one set of 3:
>
> AA BB
> 1 x
> 2 y
> 3 z
>
> To date, I haven't been able to
> figure out the answer.
> Does anyone have any ideas
> how to delete these dupe rows
> with SQL code?
>
> Happy puzzling,
>
> Argosy
>
> Sent via Deja.com http://www.deja.com/
> Before you buy.

--

---

Marc Weinstock
Logical design Solutions

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New York, New York 10006

Phone: 800.221.5327 x2136
Fax: 212-825-2245
E-Mail: MWeinstock_at_lds.com
Web: http://www.lds.com Received on Thu Nov 04 1999 - 15:47:39 CST