LINQ -如何根据仅存在于某些记录中的另一个元素选择另一个元素

// 假设有两个对象集合：orders和customers
var orders = new List<Order>
{
    new Order { OrderId = 1, CustomerId = 1, Product = "Product A" },
    new Order { OrderId = 2, CustomerId = 2, Product = "Product B" },
    new Order { OrderId = 3, CustomerId = 1, Product = "Product C" },
    new Order { OrderId = 4, CustomerId = 3, Product = "Product D" }
};

var customers = new List<Customer>
{
    new Customer { CustomerId = 1, Name = "John" },
    new Customer { CustomerId = 2, Name = "Jane" },
    new Customer { CustomerId = 3, Name = "Bob" }
};

// 使用LINQ查询，根据仅存在于orders中的CustomerId选择对应的Customer对象
var result = from order in orders
             join customer in customers on order.CustomerId equals customer.CustomerId
             select customer;

// 输出结果
foreach (var customer in result)
{
    Console.WriteLine(customer.Name);
}