MariaDB - table generation nickname utilization question.

Hi, everyone.

CREATE TABLE profession
(
    id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
    profession VARCHAR(20)
) AS
SELECT profession AS mc_prof FROM my_contacts AS mc
GROUP BY mc_prof
ORDER BY mc_prof;

You want to send a query like this to add the result to the profile field. By the way, the fields such as id and profile should be filled with column values, but the result is... The id, profile, and mc_prof fields appear, and the mc_prof fields are populated with data that must be populated by the profile. The process field that actually needs to be filled is filled with NULL.

I don't know why, so I'm posting a question. Thank you.