Create A Copy Of Missions Table Called AM_X_442_2

My solution to the following question update 10 rows. It should update only 6 records. Create a copy of the missions table called AM_X_442_2. For missions on this table that meet the following criteria:

1. within the 10 most recent missions
2. length of the first word of the mission code_name exceeds 7 characters

Change the security level to the highest security level found in missions of the same type.

UPDATE
AM_X_442_2 am
SET
am.SECURITY_LEVEL =
(
SELECT
MAX(amx.SECURITY_LEVEL)
FROM
AM_X_442_2 am
INNER JOIN
AM_X_442_2 amx
[code]....