Table Customer {
  cid integer [primary key, not null]
  firstname varchar [primary key, not null]
  lastname varchar [primary key, not null]
  preference_vcid integer [Ref: > VehicleClass.vcid, not null]
  preference_vcname varchar [Ref: > VehicleClass.vcname, not null]
}

Table VehicleClass {
  vcid integer [primary key, not null]
  vcname varchar [primary key, not null]
  length integer [not null]
  width integer [not null]
  height integer [not null]
}

Table Vehicle {
  vid integer [primary key, not null]
  vcid integer [primary key, ref: > VehicleClass.vcid, not null]
  vcname varchar [primary key, ref: > VehicleClass.vcname, not null]
  last_check_date datetime [not null]
  plate_num integer [null]
  street varchar [primary key, not null, ref: > Station.street]
  postcode varchar [primary key, not null, ref: > Station.postcode]
  city varchar [primary key, not null, ref: > Station.city]
  name varchar [primary key, not null, ref: > Station.name]
}

Table Station {
  street varchar [primary key, not null]
  postcode varchar [primary key, not null]
  city varchar [primary key, not null]
  name varchar [primary key, not null]
}

Table Reservation {
  startDateTime datetime [primary key, not null]
  endDateTime datetime [not null]
  frid integer [null, ref: > FinishedReservation.frid]
  cid integer [primary key, not null, ref: > Customer.cid]
  cname varchar [primary key, not null, ref: > Customer.firstname]
  vid integer [primary key, not null, ref: > Vehicle.vid]
}

Table FinishedReservation {
  frid integer [primary key, not null]
  distance integer [not null]
  cost integer [not null]
}