many to many relationship in MVC

Question

I am new to MVC application code first using entity framework. How to make many to many relationship in MVC..I am having more than 3 fields in joining table..please help me.

Selva Ganapathy · Answer

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

Jaganathan Bantheswaran · Answer

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; } }