Write a SQL to delete duplicate records in a table

Interview Questions and Answers

Q1. Write a SQL to delete duplicate records in a table

Ans. DELETE FROM TABLE WHERE ROW_NUM NOT IN ( SELECT MAX(ROW_ID) FROM TABLE GROUP BY DUPLICATE_FIELD )

or

DELETE FROM TABLE a WHERE ROW_ID >(SELECT MIN(ROW_ID FROM TABLE b WHERE a.DUPLICATE_FIELD=b.DUPLICATE_FIELD);

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