Entity Framework also Linq advice needed - linq

Question

i have got on my DB 3 tables
movies, workers, workermovies ( this is the Relationship table )
public class Movie
{
public Movie()
{
Genres = new List<Genre>();
Formats = new List<Format>();
ProductionCompanies = new List<ProductionCompany>();
Workers = new List<Worker>();
}
public int Id { get; set; }
public string Title { get; set; }
public DateTime ReleaseDate { get; set; }
public string StoryLine { get; set; }
public int RunTime { get; set; }
[ForeignKey("MPAARateId")]
public MPAARate MPAARate { get; set; }
public int MPAARateId { get; set; }
public byte[] ImageData { get; set; }
public string ImageMimeType { get; set; }
public DateTime CreatedDate { get; set; }
public string OfficialSite { get; set; }
public int Budget { get; set; }
public int StatusId { get; set; }
public virtual ICollection<Genre> Genres { get; set; }
public virtual ICollection<Format> Formats { get; set; }
public virtual ICollection<ProductionCompany> ProductionCompanies { get; set; }
public virtual ICollection<Worker> Workers { get; set; }
}
public class Worker
{
public int Id { get; set; }
public string FirstName { get; set; }
public string MiddleName { get; set; }
public string LastName { get; set; }
public DateTime Birthday { get; set; }
public string Biography { get; set; }
public string BornName { get; set; }
public double Height { get; set; }
public DateTime? Died { get; set; }
public byte[] ImageData { get; set; }
public string ImageMimeType { get; set; }
public bool IsActor { get; set; }
public bool IsDirector { get; set; }
public bool IsWriter { get; set; }
public bool IsProducer { get; set; }
public bool IsStar { get; set; }
public virtual ICollection<Movie> Movies { get; set; }
}
in this Relation i got the movieId and the workerId
but i also got some more fields if the person acted or writen or producer etc.
how do i define the relation entity class if needed
and when i want to get just the ppl that acted in the movie how do i wrote such a linq
query

Answer 1

You need to introduce an additional entity in your model WorkerMovie and convert the many-to-many relationship between Worker and Movie into two one-to-many relationships - one between Worker and WorkerMovie and the other between Movie and WorkerMovie. A sketch:
public class WorkerMovie
{
[Key, Column(Order = 0)]
public int WorkerId { get; set; }
[Key, Column(Order = 1)]
public int MovieId { get; set; }
public Worker Worker { get; set; }
public Movie Movie { get; set; }
public bool WorkedAsActor { get; set; }
public bool WorkedAsWriter { get; set; }
public bool WorkedAsProducer { get; set; }
// etc.
}
public class Movie
{
// ...
public virtual ICollection<WorkerMovie> WorkerMovies { get; set; }
// remove ICollection<Worker> Workers
}
public class Worker
{
// ...
public virtual ICollection<WorkerMovie> WorkerMovies { get; set; }
// remove ICollection<Movie> Movies
}
If you want only to find the workers who were actors in a particular movie with a movieId you can write:
var workersAsActors = context.WorkerMovies
.Where(wm => wm.MovieId == movieId && wm.WorkedAsActor)
.Select(wm => wm.Worker)
.ToList();
Here is another answer to a very similar question with many more examples of possible queries: Create code first, many to many, with additional fields in association table