Assuming 'id' is an identifying column and 'dupe_col' is the column with
duplicate values...
SELECT id, COUNT( dupe_col ) AS cnt
FROM tbl
GROUP BY dupe_col
HAVING cnt > 1
HTH
PB
-----
----- Original Message -----
From: Randy Chrismon
To: [EMAIL PROTECTED]
Sent: Tuesday, October 21, 2003 12:14 PM
Subject: Find non-unique values
I have a table wherein one column is SUPPOSED to be unique but I
strongly suspect isn't. Because I had this suspicion, I did not apply
a unique index to the column. Assuming there are no null values in
that column how would I find the instances of non-unique values? If I
try to alter table add unique... will it abort if the values are
non-unique, or will it drop the non-unique rows? (MyISAM tables).
There is a valid primary key on the table but (obviously) it does not
include the column in question.
Also, as this is really a SQL question (I think), is there a good
mailing list, forum, or web site devoted to SQL questions --
particularly the dialect of SQL spoken by MySQL?
Thanks.
Randy
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