Searching for records with duplicate values in a field

[david]

Hi,
Gosh I've seen this b4 but I couldn't google it, ah just found it

eg search for records having same email address

select txtemail,count(txtemail) from `tbl_user` GROUP BY txtemail
having COUNT(txtemail)>1;

and it works, is that the best way?

--
zzapper
vim -c ":%s%s*%Cyrnfr)fcbafbe[Oenz(Zbbyranne%|:%s)[[()])-)Ig|norm Vg?"
http://www.rayninfo.co.uk/tips/ vim, zsh & life tips

[Bill Karwin]

da***@tvis.co.uk wrote:

select txtemail,count(txtemail) from `tbl_user` GROUP BY txtemail
having COUNT(txtemail)>1;
and it works, is that the best way?

That's the method I use to find duplicates. That task is usually an
infrequent task, so it's not required to run very fast.

If you find a need to run this very frequently, you might consider
instead creating a UNIQUE constraint on the txtemail field. This would
prevent duplicates from being entered.

Regards,
Bill K.