DAO - UserDAO.cs - 用户表操作

    class UserDAO
    {
        public User VerifyUser(连接器, 用户名, 密码){}
        public bool GetUserByUsername(连接器, 用户名){}
        public void AddUser(连接器, 用户名, 密码){}
    }

    class UserDAO
    {
        public User VerifyUser(MySqlConnection conn, string username,string password){}
        public bool GetUserByUsername(MySqlConnection conn, string username){}
        public void AddUser(MySqlConnection conn, string username, string password){}
    }

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using MySql.Data.MySqlClient;
using GameServer.Model;
namespace GameServer.DAO
{
    class UserDAO
    {
        public User VerifyUser(MySqlConnection conn, string username,string password)
        {
            MySqlDataReader reader = null;
            try
            {
                MySqlCommand cmd = new MySqlCommand("select * from user where username = @username and password = @password", conn);
                cmd.Parameters.AddWithValue("username", username);
                cmd.Parameters.AddWithValue("password", password);
                reader = cmd.ExecuteReader();
                if (reader.Read())
                {
                    int id = reader.GetInt32("id");
                    User user = new User(id, username, password);
                    return user;
                }
                else
                {
                    return null;
                }
            }catch(Exception e)
            {
                Console.WriteLine("在VerifyUser的时候出现异常："+e);
            }
            finally
            {
                if (reader != null) reader.Close();
            }
            return null;
        }
        public bool GetUserByUsername(MySqlConnection conn, string username)
        {
            MySqlDataReader reader = null;
            try
            {
                MySqlCommand cmd = new MySqlCommand("select * from user where username = @username", conn);
                cmd.Parameters.AddWithValue("username", username);
                reader = cmd.ExecuteReader();
                if (reader.HasRows)
                {
                    return true;
                }
                else
                {
                    return false;
                }
            }
            catch (Exception e)
            {
                Console.WriteLine("在GetUserByUsername的时候出现异常：" + e);
            }
            finally
            {
                if (reader != null) reader.Close();
            }
            return false;
        }
        public void AddUser(MySqlConnection conn, string username, string password)
        {
            try
            {
                MySqlCommand cmd = new MySqlCommand("insert into user set username = @username , password = @password", conn);
                cmd.Parameters.AddWithValue("username", username);
                cmd.Parameters.AddWithValue("password", password);
                cmd.ExecuteNonQuery();
            }
            catch (Exception e)
            {
                Console.WriteLine("在AddUser的时候出现异常：" + e);
            }
        }
    }
}