How many employees does each role have? List role description, id and number of employees.
create table roles (role_description varchar, role_code varchar, PRIMARY KEY (role_description)); create table employees (role_code varchar, PRIMARY KEY (role_code))
select t1.role_description, t2.role_code, count(*) from roles as t1 join employees as t2 on t1.role_code = t2.role_code group by t2.role_code