Creating Many to Many with EF IdentityUser

Question

I want to create a Many to Many relationship with Student table and IdentityUser table that EF provides. I created a Teacher Entity and Injected "IdentityUser". Below are the entities now -

1. Student
2. Teacher : IdentityUser
3. StudentTeacher

Any guides on how to do it?

Amit Mohanty · Answer

To create a many-to-many relationship between the Student and Teacher entities you can use the StudentTeacher entity as a linking table. This table will have foreign keys to both the Student and Teacher entities. For example: public class Student { public int Id { get; set; } public string Name { get; set; } public ICollection StudentTeachers { get; set; } } public class Teacher : IdentityUser { public string FirstName { get; set; } public string LastName { get; set; } public ICollection StudentTeachers { get; set; } } public class StudentTeacher { public int StudentId { get; set; } public Student Student { get; set; } public string TeacherId { get; set; } public Teacher Teacher { get; set; } } To configure the many-to-many relationship in EF you can use the HasMany and WithMany methods in the OnModelCreating method of your DbContext. protected override void OnModelCreating(ModelBuilder modelBuilder) { modelBuilder.Entity () .HasKey(st => new { st.StudentId st.TeacherId }); modelBuilder.Entity () .HasOne(st => st.Student) .WithMany(s => s.StudentTeachers) .HasForeignKey(st => st.StudentId); modelBuilder.Entity () .HasOne(st => st.Teacher) .WithMany(t => t.StudentTeachers) .HasForeignKey(st => st.TeacherId); }

Jignesh Kumar · Answer

hello Bell Please refer this one which will help you out https://www.entityframeworktutorial.net/efcore/configure-many-to-many-relationship-in-ef-core.aspx