many to many relationship in MVC

Hi Sayli Vaidya,

        Using the following code you can handle and add many to many relationship in MVC.


    protected override void Seed(MVC4PartialViewsContext tamil)
    {
        base.Seed(tamil);

        var item1 = new Course { ItemID = 1, ItemDescripcion = "Tamil is a classical language" };
        var item2 = new Course { ItemID = 2, ItemDescripcion = "Tamil has great literature" };
        var item3 = new Course { ItemID = 3, ItemDescripcion = "Tamil is a great language" };

        tamil.Courses.Add(item1);
        tamil.Courses.Add(item2);
        tamil.Courses.Add(item3);
    }

Regards,
Selva Ganapathy K

Hi,

Consider you have Student & Course models in your project.

public class Student
{
[Key]
public int studentId {get; set;}
public List courses {get; set;} // Many courses
}

public class Course
{
[Key]
public int courseId {get; set;}
public List students {get; set;} // Many Students
}

Next, go to your DB Context class which you derived from DBContext.

It can be something

public class CourseDBContext : DbContext
{
public CourseDBContext() : base("DemoDBConnection")
{
}
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);

// M2M relations from Student to Course.

modelBuilder.Entity()x
.HasMany(c => c.courses)
.WithMany(s => s.students)
.Map (mc =>
{
mc.ToTable("StudentCourse");
mc.MapLeftKey("courseId");
mc.MapRightKey("studentId");
});

}

public DbSet Students { get; set; }
public DbSet Courses { get; set; }
}