C# 連接數據庫實現增刪改查

 class Program
    {
        private static string urls = "server=127.0.0.1;port=3306;user=root;password=123; database=abc;";
        private MySqlConnection conn;
        
        //獲取連接
        private static MySqlConnection getConnect(){
            return new MySqlConnection(urls);
        }

        //查詢
       public  void getUserData(string sql)
        {
            conn = getConnect();
            conn.Open();
            MySqlCommand cmd = new MySqlCommand(sql, conn);
            //執行ExecuteReader()返回一個MySqlDataReader對象
            MySqlDataReader reader = cmd.ExecuteReader();

            while (reader.Read())//初始索引是-1，執行讀取下一行數據，返回值是bool
            {
               // Console.WriteLine(reader[0].ToString() + reader[1].ToString() + reader[2].ToString());
               // Console.WriteLine(reader.GetInt32(0)+reader.GetString(1)+reader.GetString(2));
                Console.WriteLine(reader.GetInt32("id") + reader.GetString("name") + reader.GetString("password"));//"userid"是數據庫對應的列名，推薦這種方式
            }

            reader.Close();
            conn.Close();

        }

        //插入、刪除、更改
       public int updateUserData(string sql) 
        {
            conn = getConnect();
            conn.Open();
            MySqlCommand cmd = new MySqlCommand(sql,conn);
            int result = cmd.ExecuteNonQuery();
            return result;
        
        }

 /*  static void Main(string[] args)
        {

            Program p = new Program();
            string sql = "select *from user";
            p.getUserData(sql);

           string sql1 = "update user set name='chen',password='456' where id='1'";
            int i = p.updateUserData(sql1);
            Console.WriteLine("{0}",i);

           
           

            string sql3 = "delete from user where id='2'";
            int j = p.updateUserData(sql3);
            Console.WriteLine("{0}",j);

            string sql2 = "select *from user";
            p.getUserData(sql2);

            Console.WriteLine("hello world");
            Console.ReadLine();
        }*/
    }