public String errorText() {
    if(exception != null) {
      if(exception instanceof ClassNotFoundException) {
        return "ClassNotFoundException: " + exception.getMessage();
      }
      return exception.getMessage();
    }
    return "";
  }
Get the nth column from the row result.
The index is 0 based unlike in JDBC.
hplsql/src/main/java/org/apache/hive/hplsql/executor/QueryResult.java