How to Remove Duplicate Values from SQL Table

Learn efficient SQL methods to remove duplicates from tables using DELETE statements with subqueries and HAVING clauses. Utilize the MAX function and NOT IN operator to streamline database operations and maintain data integrity.

Below SQL queries below will help to remove duplicate values from the SQL table.

DELETE FROM table 
WHERE ID IN (
    SELECT ID
    FROM table
    GROUP BY ID
    HAVING COUNT(ID) > 1
);

DELETE FROM [master].[dbo].[EMP] 
WHERE EMP_ID NOT IN (
    SELECT MAX(EMP_ID) AS MaxRecordID
    FROM [master].[dbo].[EMP]
    GROUP BY emp_name, EMP_SALARY
)