Entity Framework - Invalid column name 'CourseLesson_Id'

Question

After trying to execute the following query:

List<CourseLesson> courseLessons = (from cl in context.CourseLessons
                                                .Include(x => x.CourseLessonTestQuestions)
                                                select cl).ToList();

I get the the error Invalid column name 'CourseLesson_Id'.

My models and DataContext looks like this(this is from a test project I've created to repreduce the problem)

public class CourseLesson
{
    public int Id { get; set; }

    public string Title { get; set; }

    public string Content { get; set; }

    public ICollection<CourseLessonTestQuestion> CourseLessonTestQuestions { get; set; }

}

public class CourseLessonTestQuestion
{

    public int Id { get; set; }

    public int CourseLessonId { get; set; }

    [ForeignKey(nameof(CourseLessonId))]
    public CourseLesson CourseLesson { get; set; }

    public int? ReturnCourseLessonId { get; set; }

    [ForeignKey(nameof(ReturnCourseLessonId))]
    public CourseLesson ReturnCourseLesson { get; set; }
}

I have 2 foreign keys that point to the same table and I'm assuming EF is trying to create or map something that doesn't really exist.

After reading for a while I've found a way to fix my problem in ( this answer ) with the following code:

            modelBuilder.Entity<CourseLessonTestQuestion>()
                .HasOptional(cltq => cltq.ReturnCourseLesson)
                .WithMany(x => x.CourseLessonTestQuestions);

What really bugs me about this situation is why everything works when I use the Fluent API, but it doesn't work with the ForeignKey attribute? This looks like something that could lead to future problems and I want to know what is really happening.

And the real question is there a solution for fixing this problem without the Fluent API? Like using attributes or some other convention?

I'm using Entity Framework 6.1.3

Answer 1

Solution without Fluent API, but with the help of InversePropertyAttribute , whose constructor's argument is the name of corresponding CourseLessonTestQuestion 's property:

public class CourseLesson
{
    public int Id { get; set; }    
    public string Title { get; set; }    
    public string Content { get; set; }

    [InverseProperty("CourseLesson")]
    public ICollection<CourseLessonTestQuestion> CourseLessonTestQuestions { get; set; }

    [InverseProperty("ReturnCourseLesson")]
    public ICollection<CourseLessonTestQuestion> ReturnCourseLessons { get; set; }    
}