I hope my question is not "off topic" really. Many users here are using node-red to store energy (gas, water, electricity meters...) consumption data to the sql table. The simple table to store kWh consumption can look like this: |ID|timestamp |kWh | |1 | 2019-07-31 14:24:25 | 270.8| …

Are those the instantaneous power readings or the accumulated total readings? I think the totals, in which case you need to take the difference between the readings at the start and end time. So if for example you needed the total for 2019-08-01 you would first have to estimate the value at the sta…

https://www.codeproject.com/Questions/878973/sum-of-values-between-two-dates this is not this case. power meter reading is going up. You can not to summarize it.

[image] Petr: this is not this case. Which "this" are your referring to?

Readings are total readings (readings from commercial power meters). And yes, it is not trivial really :smiley: It is kind of challenge :smiley: That is why I am asking here. I am really interested if other users of nod-red are bearing the same problem.

sory, my mystake, my reply was to: ukmoose ( Wattmeter data from sqlite ) https://www.codeproject.com/Questions/878973/sum-of-values-between-two-dates

Well I have provided the algorithim to use, you just have to write some code to implement it :slight_smile:

I know the algorithm. Thanks anyway. Of course I can write something complex in Python for example. But I am looking for SQL select.

You don't need to do it in python you can do it in javascript in node-red. I don't know how you would do it SQL. It may be possible but you would need an SQL expert.

I am just trying to find some node-red users bearing the same problem. I think a lot of people here are reading energy meters and are visualising data and so on... I did write SQL query already. Kind of complex. But it still has few issues ...

Node-RED

Node-RED Forum

Wattmeter data from sqlite

General

ukmoose 7 August 2019 16:10 2

https://www.codeproject.com/Questions/878973/sum-of-values-between-two-dates

Topic		Replies	Views
Reading data from an sqlite server base on time and date General sqlite	6	216	16 July 2025
Energy Dashboard + SQL General	16	254	23 December 2024
Retrieve Data from sqlite database based on the input time from date picker and moment nodes Dashboard	8	931	18 April 2022
Calculate hourly consumption General	18	4480	18 June 2020
Data get from SQLite General	52	1689	7 March 2022

Copyright OpenJS Foundation and Node-RED contributors. All rights reserved. The OpenJS Foundation has registered trademarks and uses trademarks. For a list of trademarks of the OpenJS Foundation, please see our Trademark Policy and Trademark List. Trademarks and logos not indicated on the list of OpenJS Foundation trademarks are trademarks™ or registered® trademarks of their respective holders. Use of them does not imply any affiliation with or endorsement by them.

Wattmeter data from sqlite

Related topics