Unable to combine data from multiple data sources

[artwellhlengwa12]

Hi,

Please help.

I have an issue where I need to combine data from 2 influxDB data sources into a graph. I’m using a mixed data source, then I have 2 same queries that read data from 2 data sources (A and B). I have a third expression where I’m adding the 2 queries ($A+$B). I do get a correct sum, but the issues comes when I need to group by a specific tag (e.g. entryPoint), I get a warning that indicates that fields/tags that don’t exist in both data sources have been dropped from the result.

Ideally I want to combine the tags/fields that are the same in both data sources, and if they exist in only one data source I also want to in the result/graph as it is. I tried using transformation (e.g. add field from calculation), but the fields are dynamic, I won’t know all the possible fields beforehand.

[sowdenraymond]

you can try a merge or concatenate transformation to combine your data, then you can do the math expression, using a reduce fields transformation, then all the fields should be available

[joachimschiewek]

Don’t you have a keyfield in both querys?

Then you are able do an time series outer join by field.

Jo

[artwellhlengwa12]

Hi @sowdenraymond the challenge I’m having with the transformations that I’ve tried is that I have to manually do transformations for each field, which means I need to know all the fields when I’m creating the dash/view. The issue is that the fields are added dynamically to influxDB. I need a way to dynamically combine the results of the fields with the same name without necessarily knowing the fields names

[artwellhlengwa12]

Hi @joachimschiewek the data has no key fields