중복된 값을 삭제하는 쿼리
DELETE S1 FROM table AS S1
INNER JOIN table AS S2
WHERE S1.id < S2.id AND S1.column = S2.column;
- inner join을 한 다음, id가 더 높고, 동일한 컬럼인 경우 삭제하는 쿼리
- https://www.javatpoint.com/mysql-delete-duplicate-records
DELETE S1 FROM table AS S1
INNER JOIN table AS S2
WHERE S1.id < S2.id AND S1.column = S2.column;