12、Entity Framework Core: Data Query and Object Loading Strategies

Entity Framework Core: Data Query and Object Loading Strategies

1. LINQ Data Query

1.1 Cross Join (Cartesian Product)

Cross join, also known as the Cartesian product, combines each row from one table with every row from another table. Here are two ways to perform a cross join using LINQ, along with the resulting SQL:

var flightDetailsSet3a = (from f in ctx.FlightSet
                          from b in ctx.BookingSet
                          from p in ctx.PassengerSet
                          where f.FlightNo == b.FlightNo && b.PassengerID == p.PersonID && f.Departure == "Rome"
                          select new { flight = f, passengers = p })
                         .ToList();

var flightD