Handling Null Reference Exceptions When Using LINQ with Entity Framework Core in C# 6.0
I've been struggling with this for a few days now and could really use some help... Quick question that's been bugging me - I'm testing a new approach and I've been banging my head against this for hours. I'm experiencing a frustrating scenario where my LINQ query is throwing a `NullReferenceException` when trying to access navigation properties in my Entity Framework Core model... My setup involves a simple one-to-many relationship between `Author` and `Book` entities, and I'm using C# 6.0 with EF Core 5.0. The question arises when I'm trying to include related entities while querying. Here’s the code snippet that causes the exception: ```csharp var authorsWithBooks = await _context.Authors .Include(a => a.Books) .ToListAsync(); ``` In some cases, an author might not have any books, which is expected, but I still get a `NullReferenceException` when accessing properties of `Books`. I tried checking for null values before accessing properties, but it seems this check is failing somewhere within the EF Core pipeline. To debug, I’ve added logging to see the SQL being generated, and it appears correct. Here’s what I did to set up the relationship in my model: ```csharp public class Author { public int AuthorId { get; set; } public string Name { get; set; } public virtual ICollection<Book> Books { get; set; } = new List<Book>(); } public class Book { public int BookId { get; set; } public string Title { get; set; } public int AuthorId { get; set; } public virtual Author Author { get; set; } } ``` I’ve also verified that the database is populated correctly, and it reflects the one-to-many relationship, but the exception continues to baffle me. The exact behavior message I receive is `Object reference not set to an instance of an object.` I’ve reviewed the documentation for EF Core and LINQ but haven’t found a clear solution. Any insights on how to prevent this exception or handle it more gracefully would be greatly appreciated! My development environment is Windows. Any help would be greatly appreciated! Any feedback is welcome! This is for a CLI tool running on CentOS. Any advice would be much appreciated.