Difference Between Admin and Super Admin in Database

Site admins are stored in a site option as an array of usernames.

For example, using SQL in MySQLWorkbench you can do a query such as this:

SELECT * FROM wp_sitemeta where meta_key='site_admins';

To get back a serialised PHP array. Modifying this value by adding your username and user ID will make you a site admin.

If you’re just looking to see who is a site admin, you have these functions:

get_site_admins();
is_super_admin();

If on a single site rather than a multisite, any user with the delete_users capability will be regarded as a super admin.