How to query multiple fragments in 1 api call in measurements

,
1

Product/components used and version/fix level:

Cumulocity Production

Detailed explanation of the problem:

Hi, I have measurements in this way.

{
"measurements": [
        {
            "self": "/measurement/measurements",
            "time": "2023-08-28T23:39:35.000Z",
            "id": "id",
            "source": {
                "self":  "/inventory/managedObjects/",
                "id": "id"
            },
            "type": "A",
            "A": {
                "abc": {
                    "unit": "",
                    "value": 0.0
                }
            },
{
            "self": "/measurement/measurements",
            "time": "2023-08-28T23:39:35.000Z",
            "id": "id",
            "source": {
                "self":  "/inventory/managedObjects/",
                "id": "id"
            },
            "type": "A",
            "B: {
                "xyz": {
                    "unit": "",
                    "value": 0.0
                }
            }
]
}

Now I want to fetch the latest value for all the fragments of type A. I tried

/measurement/measurements?withTotalElements=true&withTotalPages=true&revert=true&dateTo=2023-08-29T00:00:00.000Z&valueFragmentType=A&pageSize=2000&valueFragmentSeries=abc&valueFragmentSeries=xyz

this API but it is fetching only abc fragment values but not xyz values. I also tried custom query but that is also not working. Can we use custom query on measurements? If yes could you please tell me how can i carry out my use case with this? OR could you please tell me how can i achieve this use case with any other way.

Thanks,
Samanyu

2

Hi,
if you want to query multiple measurement series in one call, also take a look at the retrieve a list of series and their values measurement endpoint.
It accepts a comma separated list of series-names:
GET /measurement/measurements/series?source=...&dateFrom=...&dateTo=...&series=A.abc,B.xyz

3

Hi Korbinian,

The series endpoint won’t give me the latest value, it will only fetch the values between a time period. even if i just set dateTo as current time i have to query the series to find a value if its not present for some time like for example if the value i am searching for was entered 2 months ago, then i have to search the series endpoint till that time. I could do the same thing with measurement endpoint as well, but i dont want it to be like that. I want to fetch directly the latest values itself.

Is it possible to use custom query in measurements?
Also, could you suggest any other way?

Thanks,
Samanyu

4

If you only want to retrieve the latest measurement you will need to perform one request per combination of fragment/series.
You can use a pageSize of 1 in this case as you are only interested in the latest value.
So in your case e.g. one request to:
/measurement/measurements?revert=true&dateFrom=1970-01-01T00:00:00.000Z&pageSize=1&valueFragmentType=A&valueFragmentSeries=abc
and another one to:
/measurement/measurements?revert=true&dateFrom=1970-01-01T00:00:00.000Z&pageSize=1&valueFragmentType=A&valueFragmentSeries=xyz

There is no endpoint to retrieve the latest value of different measurement series in a single request as of now.

1 Like
5

Okay thanks for the confirmation. Could you please also tell me if it’s possible to use custom query on measurements like we do in inventory. like query = $filter= $order by creationtime desc something like that

6

The API is documented here: Cumulocity IoT - OpenAPI Specification and as you can see, this is not supported.

1 Like
7

Thanks for the confirmation :slight_smile:

8

This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.