Show the names of all employees.
select employee_name from employees
Also show their role name and role description.
select t1.employee_name, t2.role_name, t2.role_description from employees as t1 join roles as t2 on t1.role_code = t2.role_code
What is the role name and role description for the employee named Ebba?
select t2.role_name, t2.role_description from employees as t1 join roles as t2 on t1.role_code = t2.role_code where t1.employee_name = "Ebba"