How to remove duplicate data in database table
October 28th, 2006 by Ivan Uzunov
To find the duplicate data in column category_name of table named Categories you can use this SQL Query:
SELECT * FROM Categories WHERE Categories.id NOT IN
(SELECT MIN(C.id) FROM Categories AS C
WHERE Categories.category_name = C.category_name)
To delete the duplicate data you can use this SQL Query:
DELETE FROM Categories WHERE Categories.id NOT IN
(SELECT MIN(C.id) FROM Categories AS C
WHERE Categories.category_name = C.category_name)
