MySql

1、首先引用MySql.Data.dll

在MySQL\Connector NET 6.10\Assemblies\v4.5.2目录下

2、

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using MySql.Data.MySqlClient;//

namespace MySqlTest
{
    class Program
    {
        static MySqlConnection conn = null;
        static void Main(string[] args)
        {
            string connectStr = "server=127.0.0.1;port=3306;database=mygamedb;user=root;password=123456;";
            conn = new MySqlConnection(connectStr);
            try
            {
                conn.Open();
                //SelectData(conn);
                //InsertData(conn);
                //Update(conn);
                Delete(conn);
            }
            catch (Exception e)
            {
                Console.WriteLine(e);
            }
            finally
            {
                conn.Close();
            }
            Console.ReadKey();
        }

        static void SelectData(MySqlConnection conn)//查询数据
        {
            string sql = "select * from users";
            //string sql = "select id,username,password from users";

            MySqlCommand cmd = new MySqlCommand(sql, conn);
            MySqlDataReader reader = cmd.ExecuteReader();

            while (reader.Read())//返回true代表有数据，遍历所有数据
            {
                Console.WriteLine(reader[0].ToString() + reader[1].ToString() + reader[2].ToString());//方式1
                Console.WriteLine(reader.GetInt32("id"));//方式2
            }
        }

        static void InsertData(MySqlConnection conn)//插入数据
        {
            string sql = "insert into users(username,password) values('asdafqw','124134')";
            MySqlCommand cmd = new MySqlCommand(sql, conn);
            int result = cmd.ExecuteNonQuery();//返回值是数据库中受影响的行数,这里是1
            Console.WriteLine(result);
        }

        static void Update(MySqlConnection conn)//修改数据
        {
            string sql = "update users set username='wqer1',password='2134ads' where id = 9";
            MySqlCommand cmd = new MySqlCommand(sql, conn);
            cmd.ExecuteNonQuery();
        }

        static void Delete(MySqlConnection conn)//删除数据
        {
            string sql = "delete from users where id = 9";
            MySqlCommand cmd = new MySqlCommand(sql, conn);
            cmd.ExecuteNonQuery();
        }

        static void ReadUserCount(MySqlConnection conn)//查询数据个数
        {
            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);
        }

        static void ExcuteScalar(MySqlConnection conn)//查询数据个数
        {
            string sql = "select count(*) from users";

            MySqlCommand cmd = new MySqlCommand(sql, conn);

            object o = cmd.ExecuteScalar();

            int count = Convert.ToInt32(o.ToString());
            Console.WriteLine(count);
        }
        static bool VerifUser(MySqlConnection conn,string username,string password)
        {//验证数据是否存在
            string sql = "select * from users where username=@un and password =@paw";

            MySqlCommand cmd = new MySqlCommand(sql, conn);
            cmd.Parameters.AddWithValue("un", username);
            cmd.Parameters.AddWithValue("paw", password);
            MySqlDataReader reader = cmd.ExecuteReader();

            if (reader.Read())
            {
                return true;
            }
            return false;
        }
    }
}