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_at_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

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  Received on Thu Nov 04 1999 - 22:47:39 CET

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