Some dummy data for database:
-- Insert dummy data for Opleiding
INSERT INTO Opleidingen (Name)
VALUES ('Computer Science'),
       ('Electrical Engineering'),
       ('Business Administration');

-- Insert dummy data for Vak
INSERT INTO Vakken (Name, Cijfer)
VALUES 
  ('Programming', 8.5),
  ('Database Management', 7.9),
  ('Algorithms', 9.2),
  ('Digital Circuits', 7.8),
  ('Marketing Principles', 8.0);

-- Insert dummy data for Gebruiker (Student)
INSERT INTO Student(Name, Leeftijd, Woonplaats, OpleidingId)
VALUES 
  ('John Doe', 20, 'Cityville', 1),
  ('Alice Johnson', 22, 'Townsville', 2),
  ('Bob Smith', 21, 'Villagetown', 3);

-- Insert dummy data for Docent
INSERT INTO Docent (Name, Leeftijd, Woonplaats, OpleidingId, Eigenschap)
VALUES 
  ('Dr. Smith', 40, 'Townsville', 1, 'Teaching'),
  ('Prof. Brown', 35, 'Cityville', 2, 'Research'),
  ('Ms. Davis', 38, 'Villagetown', 3, 'Administration');