Tips : Howto Find MySQL Duplicates
It happen that we need to do some manual manipulations in MySQL databases, to clean data and fix things. One of my databases here have a username field which is not unique, and so full of duplicates. Don't ask me who created this db, it's something that exist!. A quick solution to retrieve duplicates is the following :
SELECT MAX(ID) as ID,USERNAME,Count(*) as c FROM `TABLE` group by USERNAME having c>1 order by ID asc
If the ID is using autoincrement, the MAX() will help to get the new values that have to be removed, or kept.
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