Use the diagram to write the SQL statements below.

1. Display first name, last name, and region name of all employees making no commission from the city of Dallas.
2. Display the country ID and number of cities we have in the country.
3. Display minimum salary of employees in each department who have commission percentage.
4. Display department id, number of employees, sum of salary, highest salary, and lowest salary of the employees of the department.

DEPARTMENTS department_id department name manager_id location_id LOCATIONS location_id street address postal code city state province Country id JOB_HISTORY employee_id start_date end_date job_id department_id EMPLOYEES employee_id first_name last_name email phone_number hire_date job_id salary commission_pct manager_id department_id COUNTRIES country_id country_name region_id JOBS job_id job_title min_salary max_salary REGIONS region_id region_name