string object to oracle check

 
        private const string getParameterValue = "SELECT parameter_name, parameter_value,parameter_subtype FROM mpb_parameter_c WHERE is_active='Y' ";
        public static DataTable GetParameterValue(string paramType, string paramName, string paramSubType="")
        {
            StringBuilder sb = new StringBuilder();
            sb.Append(getParameterValue);

            if (string.IsNullOrEmpty(paramType) == false)
            {
                sb.AppendFormat(" and parameter_type ='{0}'", paramType);
            }
            if (string.IsNullOrEmpty(paramName) == false)
            {
                sb.AppendFormat(" and parameter_name ='{0}'", paramName);
            }
            if (string.IsNullOrEmpty(paramSubType) == false)
            {
                sb.AppendFormat(" and parameter_subtype ='{0}'", paramSubType);
            }

            DbStatement stmt = dbc.DbSessionOra.GetStatement(sb.ToString());

            return dbc.DbSessionOra.ExecuteDataTable(stmt);
        }