/*
* select sum(f.price)
* from flights f, company c
* where f.companyName = c.name and c.name = "Lufthansa"
*/
public double Query6()
{
return
(FlightTable.joinFunc(
CompanyTable, t => t.Item1.CompanyName == t.Item2.Name && t.Item2.Name == "Lufthansa").Reduce(
0.0, (s, t) => s += t.Item1.Price));
}
/*
* select *
* from flights f, airport a
* where f.destinationAirport = a.name && f.destinationCity = a.city
* */
public IEnumerable <Tuple <Flight, Airport> > Query4()
{
return
(FlightTable.joinFunc
(AirportTable, t => t.Item1.DestinationAirport == t.Item2.Name &&
t.Item1.DestinationCity == t.Item2.City));
}
/*
* select f.code, f.company, a.size
* from flights f, airport a
* where f.destinationAirport = a.name && f.destinationCity = a.city && f.company = Lufthansa
* */
public IEnumerable <Tuple <string, string, AirportSize> > Query5()
{
return
(FlightTable.joinFunc(
AirportTable, t => t.Item1.DestinationAirport == t.Item2.Name &&
t.Item1.DestinationCity == t.Item2.City &&
t.Item1.CompanyName == "Lufthansa").Map(
t => new Tuple <string, string, AirportSize>(t.Item1.Code, t.Item1.CompanyName, t.Item2.Size)));
}