使用Fluent API配置1对1和多对多3个实体

public class User
{
    public int UserId { get; set; }
    public string UserName { get; set; }
    public Profile Profile { get; set; }
}

public class Profile
{
    public int ProfileId { get; set; }
    public string FullName { get; set; }
    public User User { get; set; }
}

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder.Entity<User>()
        .HasOne(u => u.Profile)
        .WithOne(p => p.User)
        .HasForeignKey<Profile>(p => p.ProfileId);
}

public class Student
{
    public int StudentId { get; set; }
    public string StudentName { get; set; }
    public ICollection<Course> Courses { get; set; }
}

public class Course
{
    public int CourseId { get; set; }
    public string CourseName { get; set; }
    public ICollection<Student> Students { get; set; }
}

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder.Entity<Student>()
        .HasMany(s => s.Courses)
        .WithMany(c => c.Students)
        .UsingEntity(j => j.ToTable("StudentCourse"));
}