使用实体框架查询来获取与其他2个表相关的表上的所有条目

public class Customer
{
    public int CustomerId { get; set; }
    public string CustomerName { get; set; }
    public List<Order> Orders { get; set; }
}

public class Order
{
    public int OrderId { get; set; }
    public int CustomerId { get; set; }
    public Customer Customer { get; set; }
    public List<OrderDetail> OrderDetails { get; set; }
}

public class OrderDetail
{
    public int OrderDetailId { get; set; }
    public int OrderId { get; set; }
    public Order Order { get; set; }
    public string ProductName { get; set; }
    public decimal UnitPrice { get; set; }
    public int Quantity { get; set; }
}

using (var context = new YourDbContext())
{
    var ordersWithDetails = context.Orders
        .Include(o => o.OrderDetails)
        .ThenInclude(od => od.Order)
        .ThenInclude(o => o.Customer)
        .ToList();

    foreach (var order in ordersWithDetails)
    {
        Console.WriteLine($"Order ID: {order.OrderId}, Customer: {order.Customer.CustomerName}");
        foreach (var detail in order.OrderDetails)
        {
            Console.WriteLine($"  Product: {detail.ProductName}, Quantity: {detail.Quantity}");
        }
    }
}