如何在连接表上使用LINQ？

// 定义顾客表
var customers = new List<Customer>
{
    new Customer { CustomerID = 1, CustomerName = "张三" },
    new Customer { CustomerID = 2, CustomerName = "李四" },
    new Customer { CustomerID = 3, CustomerName = "王五" }
};

// 定义订单表
var orders = new List<Order>
{
    new Order { OrderID = 1, CustomerID = 1, OrderDate = DateTime.Now },
    new Order { OrderID = 2, CustomerID = 2, OrderDate = DateTime.Now },
    new Order { OrderID = 3, CustomerID = 1, OrderDate = DateTime.Now },
    new Order { OrderID = 4, CustomerID = 3, OrderDate = DateTime.Now }
};

// 使用LINQ进行连接查询
var query = from c in customers
            join o in orders on c.CustomerID equals o.CustomerID
            select new { c.CustomerName, o.OrderID, o.OrderDate };

// 输出查询结果
foreach (var item in query)
{
    Console.WriteLine($"顾客：{item.CustomerName}，订单号：{item.OrderID}，订单日期：{item.OrderDate}");
}