SELECT users by wp_user_level from wordpress database

I am developing a desktop application where wordpress tables are used and only Author’s level users can login.
here’s the query:

select u.ID, u.user_login, u.user_email, u.user_nicename FROM wp_users u  
inner join wp_usermeta um ON  um.user_id = u.ID 
WHERE um.meta_key ='wp_user_level' AND um.meta_value='9';

is this right query to achieve the intended results?