The following SQL will help you see which users are site admins in a MySQL (or MariaDB) database using the
find_in_set function to query the values listed in the mdl_config siteadmins key-value.
select u.* from mdl_user u where find_in_set(u.id, (select value from mdl_config where name = 'siteadmins'))
Note you need to use
find_in_set and NOT
in as it doesn’t handle the commas returned to separate each siteadmin’s user ID.