往ORACLE数据库中插入XML数据

 public void UpdateExamXml(string xml, string RowGuid)
        {
           System.Configuration.ConfigurationManager.AppSettings["CoonString"].ToString();
            OracleConnection con = new OracleConnection(connectionString);
            con.Open();
            OracleTransaction tran = con.BeginTransaction();
            OracleCommand command = con.CreateCommand();
            command.CommandType = CommandType.Text;
            command.CommandText = "update Exam_User set ExamXml=:ExamXml where RowGuid='" + RowGuid + "'";
            OracleParameter param = command.CreateParameter();
            param.ParameterName = ":ExamXml";
            param.Value = xml;
            param.OracleDbType = OracleDbType.NClob;
            command.Parameters.Add(param);
            command.ExecuteNonQuery();
            tran.Commit();
            con.Close();
        }