构建Linq表达式

using System;
using System.Data.Linq;
using System.Data.Linq.Mapping;
using System.Linq;

public class Customer
{
    public int Id { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public string Email { get; set; }
}

public class CustomerContext : DataContext
{
    public Table<Customer> Customers { get { return GetTable(); } }
}

class Program
{
    static void Main(string[] args)
    {
        CustomerContext context = new CustomerContext();

        // 构建Linq表达式
        IQueryable<Customer> query = from customer in context.Customers
                                    where customer.Email == "example@example.com"
                                    select customer;

        // 执行查询
        foreach (Customer customer in query)
        {
            Console.WriteLine($"Customer ID: {customer.Id}");
            Console.WriteLine($"Customer Name: {customer.FirstName} {customer.LastName}");
            Console.WriteLine($"Customer Email: {customer.Email}");
        }

        // 关闭数据库连接和Linq表达式
        context.Dispose();
    }
}