Find duplicate value in a table

you want to find all Employe names  in a table that exist more than once:

SELECT EName, COUNT(EName) AS NumOccurrences FROM users GROUP BY EName HAVING ( COUNT(EName) > 1 ) You could also use this technique to find rows that occur exactly once:

SELECT EName FROM users GROUP BY EName HAVING ( COUNT(EName) = 1 )

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