I am creating and populating a MySQL table using the following query:

SET time_zone = ' 00:00'; CREATE TABLE timestamp_n_datetime ( id INT, time DATETIME, avg_time DATETIME ); INSERT INTO timestamp_n_datetime(id,time,avg_time) VALUES("1","2023-01-03 10:12:13", NULL), ("1", "2023-02-04 11:13:14", NULL), ("2", "2023-03-02 09:14:10", NULL), ("2", "2023-04-02 05:15:50", NULL), ("1", "2023-06-10 02:04:10", NULL);

I want to populate the "avg_time" column with the average of the "time" column grouped by id. For example, the first row has 'id' = 1, so the 'avg_time' column should take the average of the first, second, and fifth rows since their 'id' is also 1.

How should I answer this question?

Edit: To clarify, I want to convert all the DATETIME columns to milliseconds, add them all up, and then divide by the added number. For example, for id=2, converting them to milliseconds, adding them and then dividing by 2 (since there are two rows with "id" = 2) gives the average for March 17, 2023 at 5:45:00 PM. I want to get the average this way.