This page is to help create, manage, and display n:n relationships – here are some steps (there are many ways to do this).
The end goal of this tutorial will be to create a Grade sheet that shows many to many relationship between grades and students like this
Step 1. In my project I am going to do this the fastest way by simply creating an Entity Data Model in one step. I already have an existing project and I select Add New Item by right clicking on the Models folder.
I am going to create an Empty Entity Framework Model and fill it in from the database
This will allow you to view the model – of course we do not have one yet – I am going to Read a Model from the Database in MVC.
Once you have uploaded a model from the database you will see it in your model browser.
And here is your code – should look familiar with what you would expect in an n:n relationship
class Class
namespace SampleNtoN.Models
{
using System;
using System.Collections.Generic;
public partial class Class
{
[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")]
public Class()
{
this.Grades = new HashSet<Grade>();
}
public int ClassId { get; set; }
public string ClassName { get; set; }
[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
public virtual ICollection<Grade> Grades { get; set; }
}
}class Student
namespace SampleNtoN.Models
{
using System;
using System.Collections.Generic;
public partial class Student
{
[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")]
public Student()
{
this.Grades = new HashSet<Grade>();
}
public int StudentId { get; set; }
public string StudentName { get; set; }
[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
public virtual ICollection<Grade> Grades { get; set; }
}
}class Grades
namespace SampleNtoN.Models
{
using System;
using System.Collections.Generic;
public partial class Grade
{
public int GradeId { get; set; }
public int StudentId { get; set; }
public int ClassId { get; set; }
public string Grade1 { get; set; }
public virtual Class Class { get; set; }
public virtual Student Student { get; set; }
}
}