scenarios in ASP.NET Core 6.0 with EF Core when configuring a many-to-many relationship
I'm trying to debug I'm trying to figure out Quick question that's been bugging me - I'm working with an scenario while trying to set up a many-to-many relationship between two entities, `Student` and `Course`, in my ASP.NET Core 6.0 application using Entity Framework Core 6.0. I created a join entity called `StudentCourse` to handle this relationship. However, when I attempt to save changes to the database, I get the following behavior: ``` DbUpdateException: An behavior occurred while updating the entries. See the inner exception for details. ``` It seems like the mapping isn't configured correctly. I've tried setting it up using the Fluent API as follows: ```csharp public class ApplicationDbContext : DbContext { public DbSet<Student> Students { get; set; } public DbSet<Course> Courses { get; set; } public DbSet<StudentCourse> StudentCourses { get; set; } protected override void OnModelCreating(ModelBuilder modelBuilder) { modelBuilder.Entity<StudentCourse>() .HasKey(sc => new { sc.StudentId, sc.CourseId }); modelBuilder.Entity<StudentCourse>() .HasOne(sc => sc.Student) .WithMany(s => s.StudentCourses) .HasForeignKey(sc => sc.StudentId); modelBuilder.Entity<StudentCourse>() .HasOne(sc => sc.Course) .WithMany(c => c.StudentCourses) .HasForeignKey(sc => sc.CourseId); } } ``` And my `Student` and `Course` classes look like this: ```csharp public class Student { public int Id { get; set; } public string Name { get; set; } public ICollection<StudentCourse> StudentCourses { get; set; } } public class Course { public int Id { get; set; } public string Title { get; set; } public ICollection<StudentCourse> StudentCourses { get; set; } } public class StudentCourse { public int StudentId { get; set; } public Student Student { get; set; } public int CourseId { get; set; } public Course Course { get; set; } } ``` When I try to add a new student and assign some courses, the behavior is thrown. I've confirmed that the `Student` and `Course` entities are being tracked by the context. Here’s the code I’m using to add a new student with courses: ```csharp var student = new Student { Name = "John Doe" }; var course1 = new Course { Title = "Mathematics" }; var course2 = new Course { Title = "Science" }; student.StudentCourses = new List<StudentCourse> { new StudentCourse { Student = student, Course = course1 }, new StudentCourse { Student = student, Course = course2 } }; _context.Students.Add(student); _context.SaveChanges(); ``` I verified that the database schema matches my models, and `StudentCourse` is being created in the migration. But whenever I try to save changes, I encounter the `DbUpdateException`. Any ideas on what might be going wrong or how to troubleshoot this further? My development environment is Ubuntu. I'd really appreciate any guidance on this. I recently upgraded to Csharp latest. What would be the recommended way to handle this? My team is using Csharp for this web app. I'm open to any suggestions.