eager-loading.cs

using (var context = new OrderingDbContext())
{
    // Load all Orders and related Line Items
    var orders = context.Order
                        .Include(b => b.LineItem)
                        .ToList();
                        
    // Load an Order and it's related Line Items
    var orders = context.Order
                        .Where(x => x.OrderId == orderId)
                        .Include(b => b.LineItem)
                        .ToList();
                        
    // Multiple levels deep
    // Load all order, all related line items, and all related reviews for that line item (product)
    var orders1 = context.Order
                        .Include(b => b.LineItem.Select(p => p.Review))
                        .ToList();
}