C#中MySql帮助类

在C#中使用MySql数据库可以使用MySql.Data.MySqlClient命名空间中提供的类来实现，这些类可以通过ADO.NET来访问数据库。但是，为了方便使用，我们可以封装一个帮助类来进行数据库操作，以下是一个简单的MySql帮助类的示例代码：

using System;
using System.Collections.Generic;
using MySql.Data.MySqlClient;

namespace MySqlHelper
{
    public class MySqlHelper
    {
        private string connectionString;

        public MySqlHelper(string connectionString)
        {
            this.connectionString = connectionString;
        }

        public List<string> ExecuteQuery(string query)
        {
            List<string> results = new List<string>();

            using (MySqlConnection connection = new MySqlConnection(connectionString))
            {
                connection.Open();

                using (MySqlCommand command = new MySqlCommand(query, connection))
                {
                    using (MySqlDataReader reader = command.ExecuteReader())
                    {
                        while (reader.Read())
                        {
                            results.Add(reader.GetString(0));
                        }
                    }
                }
            }

            return results;
        }

        public int ExecuteNonQuery(string query)
        {
            int rowsAffected = 0;

            using (MySqlConnection connection = new MySqlConnection(connectionString))
            {
                connection.Open();

                using (MySqlCommand command = new MySqlCommand(query, connection))
                {
                    rowsAffected = command.ExecuteNonQuery();
                }
            }

            return rowsAffected;
        }
    }
}

这个帮助类包含了两个方法：ExecuteQuery和ExecuteNonQuery。ExecuteQuery方法用于执行查询语句并返回结果集，ExecuteNonQuery方法用于执行不返回结果集的语句，例如插入、更新和删除语句。

使用示例：

using System;
using MySqlHelper;

namespace Test
{
    class Program
    {
        static void Main(string[] args)
        {
            string connectionString = "server=localhost;database=mydb;uid=myuser;password=mypass;";
            MySqlHelper helper = new MySqlHelper(connectionString);

            // 查询
            string query = "SELECT name FROM users;";
            var results = helper.ExecuteQuery(query);
            foreach (var result in results)
            {
                Console.WriteLine(result);
            }

            // 插入
            string insertQuery = "INSERT INTO users (name, age) VALUES ('John', 30);";
            int rowsAffected = helper.ExecuteNonQuery(insertQuery);
            Console.WriteLine(rowsAffected + " rows affected.");
        }
    }
}