implementing Lazy Loading Navigation Properties in EF Core 7 Causing Unexpected Null References
I tried several approaches but none seem to work... I'm currently working on a .NET 7 application using Entity Framework Core 7, and I've run into an scenario with lazy loading of navigation properties. I have a `Blog` entity that includes a collection of `Posts`, and I'm trying to access these posts through a lazy-loaded property. However, when I attempt to access the `Posts` property, I occasionally get a `NullReferenceException`, even though I expect it to be fully populated. Here's a simplified version of my code: ```csharp public class Blog { public int Id { get; set; } public string Title { get; set; } public virtual ICollection<Post> Posts { get; set; } } public class Post { public int Id { get; set; } public string Content { get; set; } public int BlogId { get; set; } public virtual Blog Blog { get; set; } } // In my data access code var blog = await _context.Blogs.FindAsync(blogId); var posts = blog.Posts; // This line sometimes throws NullReferenceException ``` I've ensured that lazy loading is enabled in my `DbContext` setup: ```csharp services.AddDbContext<MyDbContext>(options => options.UseLazyLoadingProxies().UseSqlServer(connectionString)); ``` I also tried eagerly loading the `Posts` using `.Include()` to see if the question still persisted: ```csharp var blog = await _context.Blogs.Include(b => b.Posts).FirstOrDefaultAsync(b => b.Id == blogId); ``` This approach works, but it's not ideal for all scenarios since sometimes I want to fetch `Blog` entities without their `Posts`. I've also checked that the database is correctly populated with related records and that the foreign key relationships are intact. It seems like there is an intermittent scenario. Does anyone have insights on why I might be getting null reference exceptions during lazy loading? Is there a possibility of some threading issues, or is it purely related to how lazy loading is being handled in this context? Any help would be greatly appreciated! I'm working on a CLI tool that needs to handle this.