SQL: Get all administrators

get-admins.sql

SELECT u.ID, u.user_login, u.user_nicename, u.user_email FROM wp_users u INNER JOIN wp_usermeta m ON m.user_id = u.ID WHERE m.meta_key = 'wp_capabilities' AND m.meta_value LIKE '%admin%' ORDER BY u.user_registered

SELECT u.ID, u.user_login, u.user_nicename, u.user_email FROM myprefix_users u INNER JOIN myprefix_usermeta m ON m.user_id = u.ID WHERE m.meta_key = 'myprefix_capabilities' AND m.meta_value LIKE '%admin%' ORDER BY u.user_registered

For more information, see the tutorial here: http://wpsmith.net/2014/snippets/popular-wordpress-sql-user-administration-scripts/