[ c# ] MySqlConnector 로 mysql select , insert

public class TestResultDTO
    {
        public int id { get; set; }
        public string name { get; set; }
        public float score { get; set; }
    }

insert and select 

public class MysqlConnector
    {
        private MySqlConnection connection = new MySqlConnection("Server=severip;User ID=id;Password=password;Database=db_name;Port=port");
        public MysqlConnector()
        {
            connection.Open();
        }

        public void MysqlConnectorSelect(string date)
        {
            List<TestResultDTO> resultList = new List<TestResultDTO>();
            if (connection.State != System.Data.ConnectionState.Open) connection.Open();
           
                string sql = "select id , table_name.NAME ,score from table_name where score >= 85 ";

                var command = new MySqlCommand(sql, connection);           
                // command.CommandTimeout = 9000000;

                var reader = command.ExecuteReader();
                while (reader.Read())
                    {

                        TestResultDTO result = new TestResultDTO();
                        result.Name =  reader.GetInt32(0);
                        result.Detecttime =  reader.GetString(1);
                        result.Countvalue = reader.GetFloat(2);
                        

                        resultList.Add(result);
                    }
            
            
            // Console.WriteLine(resultList.Count());
            connection.Close();
        }
        
        public void MysqlConnectorInsert(TestResultDTO result)
        {
            string insertQuery = String.Format("INSERT INTO table_name (id,name,score) VALUES('{0}','{1}','{2}')"
                            , result.id,  result.name, result.score);

            MySqlCommand command = new MySqlCommand(insertQuery, connection);

            //if (command.ExecuteNonQuery() == 1)
            //{
            //    Console.WriteLine("인서트 성공");
            //}
            //else
            //{
            //    Console.WriteLine("인서트 실패");
            //}
        }
    }