Chapter four: extra exercises

Tables:

 Table  Primary Key  Attributes
 Employee  eID  eLast, eFirst, eTitle, eSalary
 TechnologyArea  aID  aTitle, aURL, aLeadID
 TrainingCourse  cID  cTitle, cHours, areaID
 Takes  eID, cID  tYear, tMonth, tDay

Queries:

  1. What training courses are offered in the 'Database' technology area?
  2. Which employees have taken a training course offered in the 'Database' technology area?
  3. Which employees have not taken any training course?
  4. Which employees took courses in more than one technology area?
  5. Which employees have the minimum salary?
  6. Which employees took all of the training courses offered in the 'Database' technology area?
  7. Display the last names of the employees in alphabetical order and within that display their salary in descending order.
  8. Display the minimum, maximum and average employee salary, as well as the sum of all salaries and a count of the number of employees in the database.
  9. Give the number of employees that took a training course in the database technology area.
  10. Display the minimum, maximum and average employee salary of employees by title.
  11. Display the identification number of the technology area, its title and the number of employees.
  12. Display the areas with at least 4 employees that took training courses in that technology area and display the result in descending order on the number of employees.