display the department id and the total salary for those departments which contains at least two employees.
select department_id, sum ( salary ) from employees group by department_id having count ( * ) > = 2
What are the first and last names of employees in department id 90?
select first_name, last_name from employees where department_id = 90
What department id is Steven King in?
select department_id from employees where first_name = 'Steven' and last_name = 'King'
What is Steven King's Salary and Job id?
select job_id,salary from employees where first_name = 'Steven' and last_name = 'King'
What is the highest salary and what employee id has it?
select employee_id,salary from employees order by salary desc limit 1