LINQ to Objects - advanced patterns When Filtering Nested Collections in C#
I keep running into I'm working on a personal project and I'm relatively new to this, so bear with me..... I'm trying to filter a list of `Order` objects, where each order contains a list of `Product` objects. The goal is to retrieve orders that contain at least one product with a specific attribute, but I keep running into an unexpected behavior where my filter doesn't seem to work correctly. I'm using .NET 6 and the following classes: ```csharp public class Order { public int OrderId { get; set; } public List<Product> Products { get; set; } } public class Product { public string Name { get; set; } public bool IsActive { get; set; } } ``` Here's the LINQ query I've written to filter the orders: ```csharp var filteredOrders = orders.Where(order => order.Products.Any(product => product.IsActive)).ToList(); ``` However, I'm noticing that even when there are no active products in an order, the order still appears in the `filteredOrders` list. I've double-checked my data, and all orders have products, but the `IsActive` property is only `true` for some products. To help debug, I added the following logging: ```csharp foreach (var order in orders) { Console.WriteLine($"Order {order.OrderId} has active products: {order.Products.Any(p => p.IsActive)}"); } ``` This outputs `true` for orders that should not be included. I'm not sure if there's an scenario with the way I'm querying or if there's something else at play here. I've also tried breaking it down into separate steps: ```csharp var activeProducts = orders.SelectMany(order => order.Products).Where(product => product.IsActive); var ordersWithActiveProducts = orders.Where(order => order.Products.Intersect(activeProducts).Any()).ToList(); ``` This approach still yields incorrect results. Is there something Iām missing in my LINQ statement, or is there a more efficient way to achieve this? Any insights would be greatly appreciated! For context: I'm using C# on macOS. Thanks in advance! I'm working with C# in a Docker container on Debian. Could this be a known issue? For context: I'm using C# on macOS. Thanks, I really appreciate it! My team is using C# for this mobile app. What am I doing wrong?