实体框架如何使用代码优先方法生成此SQL代码？

Question

I have 2 tables that should look like this

• flights : flight_id, route_id,...
• routes : route_id,...

I am new to Entity Framework and can't figure out how to write model classes so well, I have tried this way:

public class Flight
{
    [Key]
    public int flight_id { get; set; }
    [ForeignKey("route_id")]
    public int route_id { get; set; }
    public int airline_id { get; set; }
    public DateTime departure_time { get; set; }
    public DateTime arrival_time { get; set; }
}

public class Route
{
    [Key]
    public int route_id { get; set; }
    public int origin_city_id { get; set; }
    public int destination_city_id { get; set; }
    public DateTime departure_date { get; set; }
}

and I would like to get as a result

ALTER TABLE [dbo].[Flights]
    ADD CONSTRAINT [FK_dbo.Flights_dbo.route_id] 
        FOREIGN KEY ([route_id]) REFERENCES [dbo].[Routes] ([route_id]) 
        ON DELETE CASCADE;

Answer 1

You need to include the model Route in order for you reference it to your model Flight . As I can see that you are doing a 1:n relationship, you can do it like this:

public class Flight
{
        [Key]
        public int flight_id { get; set; }
        [ForeignKey("route_id")]
        public int route_id { get; set; }
        public int airline_id { get; set; }
        public DateTime departure_time { get; set; }
        public DateTime arrival_time { get; set; }
        public List<Route> Routes {get; set} //including the Route Model for 
                                             //you to properly reference it.
}

You can remove the List if you want a 1:1 relationship so that it would look like this:

public Route Routing {get; set;}