DELETE A Duplicate Row by id code example
Example 1: mysql remove duplicates
DELETE FROM table_name WHERE id
NOT IN ( SELECT id FROM table_name
GROUP BY field_1, field_2)
Example 2: sql server delete records that have a single duplicate column
WITH cte AS (
SELECT
contact_id,
first_name,
last_name,
email,
ROW_NUMBER() OVER (
PARTITION BY
first_name,
last_name,
email
ORDER BY
first_name,
last_name,
email
) row_num
FROM
sales.contacts
)
DELETE FROM cte
WHERE row_num > 1;