Stream data access

The area streamData allows access to stored time series data. Let's start with simple sample that requests the voltage value of all energy meters by their timestamp.

query {
  streamData {
    tsIndustryEnergyEnergyMeter {
      items {
        rtId
        ckTypeId
        timeStamp
        voltage
      }
    }
  }
}

A response to this query can look like the following:

{
  "data": {
    "streamData": {
      "tsIndustryEnergyEnergyMeter": {
        "items": [
          {
            "rtId": "65dc6d24cc529cdc46c84fcc",
            "ckTypeId": "Industry.Energy/EnergyMeter",
            "timeStamp": "2024-03-21T16:22:47.676Z",
            "voltage": 4.04196210149963
          },
          {
            "rtId": "65dc6d24cc529cdc46c84fcc",
            "ckTypeId": "Industry.Energy/EnergyMeter",
            "timeStamp": "2024-03-21T16:23:50.675Z",
            "voltage": -9.00808094383129
          }
        ]
      }
    }
  }
}

Pagination

Both runtime and stream data can be paginated to manage large datasets effectively. Pagination is achieved through the use of the first and after arguments in GraphQL queries. The first argument specifies the number of items to return, while the after argument indicates the cursor position to start fetching data.

Example query with pagination:

query {
  streamData {
    tsIndustryEnergyEnergyMeter(first: 2, after: "YXJyYXljb25uZWN0aW9uOjE=") {
      pageInfo {
        endCursor
        hasNextPage
      }
      items {
        rtId
        ckTypeId
        timeStamp
        voltage
      }
    }
  }
}

This query returns the first two items after the cursor position specified by the after argument. The response includes the endCursor and hasNextPage fields, which help manage pagination effectively.

Pagination​

Pagination