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 ...

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Wattmeter data from sqlite

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ukmoose 7 August 2019 16:10 2

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

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Wattmeter data from sqlite

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