airport

The Company table contains IDs and names of the airlines transporting passengers. The Trip table contains information on the schedule of flights: trip (flight) number, company (airline) ID, plane type, departure city, destination city, departure time, and arrival time. The Passenger table holds IDs and names of the passengers. The Pass_in_trip table contains data on flight bookings: trip number, departure date (day), passenger ID and her seat (place) designation during the flight. It should be noted that

• scheduled flights are operated daily; the duration of any flight is less than 24 hours; town_from <> town_to;
• all time and date values are assumed to belong to the same time zone;
• departure and arrival times are specified with one minute precision;
• there can be several passengers bearing the same first name and surname (for example, Bruce Willis);
• the seat (place) designation consists of a number followed by a letter; the number stands for the row, while the letter (a – d) defines the seat position in the grid (from left to right, in alphabetical order;
• connections and constraints are shown in the database schema below.