Question

I have two classes Car and Drivers:

public class Car
{
    public string Status { get; set; }
    public IList<Driver> Event { get; set; }
}

public class Driver
{
    public string Name { get; set; }
    ....
}

I get the values from TWO SQL-Statemens (e.g. Select * from car; select * from driver). I can fill the first one with:

while (rdr.Read())
{
    _results.Add(new TaskModel(rdr));
    //new TaskModel(rdr); 
}

where _results is:

private ObservableCollection<Car> _results = new ObservableCollection<Car>();

Constructor for Car looks like:

public Car(IDataRecord record)
{
    this.CarId = Convert.ToInt32(record["CARID"]);
    this.Color = (string)record["COLOR"];
}

I’m asking myself how to fill the datareader with two statemens and refer in the constructor to get the whole object (Car with Driver)

Answer 1

How about retrieving all the data in one go, as in

SELECT * FROM Car INNER JOIN Driver ON Car.Id = Driver.CarId

And then create your object graph from there on?

Also I wouldn’t use the datareader in the constructor, use a third object to construct the object from a database.

JOIN Fundamentels.