cannot get data when using some features implemented in iotdb session

[yooniversal]

I have implemented that change default DB of edgeX project as IoTDB working on docker, but there are some issues when use GET method when I call it on edgeX. IoTDB session is connected successfully with DB client of the project.

Description

I'm following printDataSet0() and insertRecord() implemented in session_example.go.

Although Session.InsertRecord() works successfully that returns no error and I can check input data in IoTDB (referenced here for testing it work as typing SQL in IoTDB), cannot retrieve the data in edgeX when use Session.ExecuteQueryStatement(sql) perfectly. More details, ExecuteQueryStatement() returns SessionDataSet without error but when use SessionDataSet.GetText(), it returns "" always but not input data saved in IoTDB.

Use InsertRecord() in AddEvent(): code here and GetText() in ChangeTypeToEvent(): code here

execute SQL in IoTDB:

empty string returned from IoTDB in edgeX API response: (deviceId: root.sg27, measurement: deviceName, value: root)

While I use getText(), make isNull() in the function not working because returns false:

// client/rpcdataset.go
func (s *IoTDBRpcDataSet) getText(columnName string) string {
    if s.closed {
        return ""
    }
    if columnName == TimestampColumnName {
        return time.Unix(0, bytesToInt64(s.time)*1000000).Format(time.RFC3339)
    }

    columnIndex := s.getColumnIndex(columnName)
    if columnIndex < 0 || int(columnIndex) >= len(s.values) || { //s.isNull(int(columnIndex), s.rowsIndex-1) {
        s.lastReadWasNull = true
        return ""
    }
    s.lastReadWasNull = false
    return s.getString(int(columnIndex), s.columnTypeDeduplicatedList[columnIndex])
}

• len(s.values) is updated (equal with expected value) but it has no value
• SessionDataSet.GetColumnCount() is updated too and equals with expected value
• But if isNull() is activated, then error occured: runtime error: negative shift amount
  • When the error is ocurred, isNull()'s parameters columnIndex=0, rowsIndex=0 So in isNull(), parameter rowsIndex has -1 which makes the error because shift operation must be used with non-negative value

Question

• (edited) I think columnIndex and rowsIndex must be updated whenever POST event occurs. But rowsIndex is not. Is there any reason why not update it?
• In IoTDB, whenever get data from database if encounters SQL query, it calls ExecuteQueryStatement()? (or ExecuteStatement() or ExecuteRawDataQuery() whatever)

If you think reason is different, please share.

Environment

• IoTDB: 1.0.0-standalone (on docker)
• OS: Ubuntu 22.04.1 LTS

[yooniversal]

I omitted some codes that must be called SessionDataSet.Next() before calling SessionDataSet.GetText() (or SessionDataSet.GetValue(), ...). After adding some codes in session_example.go, GetText() and GetValue() return expected value.