Question

I have a mysql table like this:

   id   employee_number  name
    1        1             A
    2        2             B
    3        3             C
    4        3             C
    5        4             D
    6        5             E
    7        5             E            
    8        6             F
    9        7             G
    8        8             H
    9        9             I
   10      ....    
   11      ....
   12      ....
        many duplicated 
        employee_number

I want to remove 1 row of employee_number 3 and 5(id 3 or 4 and 6 or 7 don’t matter).
I can see the duplicated rows with the following sql but not sure what to do next. I apprciate if someone can help me out on this one. Thanks a lot!

SELECT COUNT( id ) , employee_number
FROM  `employees` 
GROUP BY employee_number

Updated:

CREATE TABLE new_table as
SELECT * FROM old_table WHERE 1 GROUP BY employee_number;

Well. I found this statements and it works. Thanks guys.

Answer 1

DELETE FROM `employees`
WHERE ID 
NOT IN 
(SELECT MAX(B.ID) FROM 
                  (SELECT employee_number
                   FROM `employees`
                   GROUP BY employee_number
                   HAVING COUNT(*)>1) A,
                   `employees` B
 WHERE A.employee_number=B.employee_number
 GROUP BY B.employee_number
);