使用linq从连接表中选择

using System;
using System.Collections.Generic;
using System.Linq;

public class Customer
{
    public int Id { get; set; }
    public string Name { get; set; }
}

public class Order
{
    public int Id { get; set; }
    public int CustomerId { get; set; }
    public decimal Amount { get; set; }
}

public class Program
{
    public static void Main()
    {
        // 准备要连接的两个表
        List<Customer> customers = new List<Customer>
        {
            new Customer { Id = 1, Name = "Alice" },
            new Customer { Id = 2, Name = "Bob" },
            new Customer { Id = 3, Name = "Charlie" }
        };

        List<Order> orders = new List<Order>
        {
            new Order { Id = 1, CustomerId = 1, Amount = 100 },
            new Order { Id = 2, CustomerId = 2, Amount = 200 },
            new Order { Id = 3, CustomerId = 1, Amount = 300 },
            new Order { Id = 4, CustomerId = 3, Amount = 400 }
        };

        // 使用Join操作符连接两个表，并选择需要的字段
        var query = from customer in customers
                    join order in orders on customer.Id equals order.CustomerId
                    select new { CustomerName = customer.Name, OrderAmount = order.Amount };

        // 执行查询，输出结果
        foreach (var result in query)
        {
            Console.WriteLine($"Customer: {result.CustomerName}, Order Amount: {result.OrderAmount}");
        }
    }
}