笔记二：客户端输入，服务端检测用户密码是否正确

来源：互联网发布：淘宝落地页是什么编辑：程序博客网时间：2024/06/05 14:29
using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;using MySql.Data.MySqlClient;namespace CsharpToMySQL{    class Program    {        static void Main(string[] args)        {            Console.WriteLine(VerifyUser("ycb", "89"));            Console.ReadKey();        }        static bool VerifyUser(string username,string password) {                            string connectStr = "server=127.0.0.1;port=3306;database=mygamedb;user=root;password=root;";            MySqlConnection conn = new MySqlConnection(connectStr);            try            {                conn.Open();                //string sql = "select * from users where username= '" + username + "' and password=' " + password + "'";                string sql = "select *from users where username =@para1 and password =@para2";                MySqlCommand cmd = new MySqlCommand(sql, conn);                cmd.Parameters.AddWithValue("para1", username);                cmd.Parameters.AddWithValue("para2", password);                MySqlDataReader reader = cmd.ExecuteReader();                if (reader.Read())                {                    conn.Close();                    return true;                }             }            catch (Exception e)            {                Console.WriteLine(e.ToString());            }            finally            {                conn.Close();            }            return true;        }        static void Insert()        {            string connectStr = "server=127.0.0.1;port=3306;database=mygamedb;user=root;password=root;";            MySqlConnection conn = new MySqlConnection(connectStr);            try            {                conn.Open();                string sql = "insert into users(username,password,registerdate) values('ycb4','89','" + DateTime.Now + "')";                MySqlCommand cmd = new MySqlCommand(sql, conn);                int result = cmd.ExecuteNonQuery(); //返回值是数据库中受影响的数据行数            }            catch (Exception e)            {                Console.WriteLine(e.ToString());            }            finally            {                conn.Close();            }        }        static void Update()        {            string connectStr = "server=127.0.0.1;port=3306;database=mygamedb;user=root;password=root;";            MySqlConnection conn = new MySqlConnection(connectStr);            try            {                conn.Open();                string sql = "update   users set username='new ycb',password='775'where id = 4";                MySqlCommand cmd = new MySqlCommand(sql, conn);                int result = cmd.ExecuteNonQuery(); //返回值是数据库中受影响的数据行数            }            catch (Exception e)            {                Console.WriteLine(e.ToString());            }            finally            {                conn.Close();            }        }        static void ReadUsersCount() {            string connectStr = "server=127.0.0.1;port=3306;database=mygamedb;user=root;password=root;";            MySqlConnection conn = new MySqlConnection(connectStr);            try            {                conn.Open();                string sql = "select count(*) from users";                MySqlCommand cmd = new MySqlCommand(sql, conn);                MySqlDataReader reader = cmd.ExecuteReader();                reader.Read();                int count = Convert.ToInt32(reader[0].ToString());                Console.WriteLine(count);            }            catch (Exception e)            {                Console.WriteLine(e.ToString());            }            finally            {                conn.Close();            }        }        static void ExcuteScalar ()        {            string connectStr = "server=127.0.0.1;port=3306;database=mygamedb;user=root;password=root;";            MySqlConnection conn = new MySqlConnection(connectStr);            try            {                conn.Open();                string sql = "select count(*) from users";                MySqlCommand cmd = new MySqlCommand(sql, conn);                object res = cmd.ExecuteScalar();                int count = Convert.ToInt32(res.ToString());                Console.WriteLine(count);            }            catch (Exception e)            {                Console.WriteLine(e.ToString());            }            finally            {                conn.Close();            }        }    }}
阅读全文
0 0