Removing domain from sql query results

Say I use the command:

Select Username, UserType from USERS_DATABASE;

And i get the next results:

Username:            UserType:         
someDomain/user1      User
someDomain/user2      User
diffDomain/user3      User

Is there any way i can remove the domain through an SQL query or I need to parse it and then remove?

The domains can be different (Length, Characters and so on)

Thanks.