I just noticed that a key field (emailaddress) in my db is case
sensitive when it should not have been, so now I've got a bunch of
what are effectively duplicate records. I'm having trouble picking
them out so I can manually merge/delete them before changing the
collation on the field to be case insensitive.
SELECT * FROM mytable group by lower(emailaddress) having count
(emailaddress) > 1
This is ok, but it only shows me the records with lower case
addresses (I can't tell which case version is the correct one without
looking at them) when I want to see the records with all cases, that
is all of 'joe@stripped', 'Joe@stripped' and 'JOE@stripped'.
I'm confusing myself with the case sensitivity and self-references!
I think there are about 45 duplicates out of about 200,000.
How can I find these pesky things?
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