← All workshopsRead Did the High Value Belong to the Temperature Sensor?

NoSQL

Find high temperatures without borrowing another sensor’s value

BOTIE

Expand readings while retaining asset_id. Follow the kind and value belonging to each member.
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0 passed · 0 failed · 1 not run

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Received result

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Examples, experiments and workspace controls
Live values

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Use a copy of the example to try your own data. Keep the problem's assumptions in mind, and predict the effect of a change before checking the output. You can also add another branch to compare two ways of doing the calculation.

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Context for this challenge

Expand readings while retaining asset_id. Follow the kind and value belonging to each member.

Each pump contains an array of typed readings.

Inspect the component calculation
Make one row per array member(
  Documents: Pump documents and readings
  Array field: readings
)
Examples and results
Pump documents and readings
[
  {
    "asset_id": "P1",
    "readings": [
      {
        "kind": "temperature",
        "value": 85
      }
    ]
  },
  {
    "asset_id": "P2",
    "readings": [
      {
        "kind": "temperature",
        "value": 65
      }
    ]
  }
]
Required result
[
  {
    "asset_id": "P1",
    "readings": {
      "kind": "temperature",
      "value": 85
    }
  },
  {
    "asset_id": "P2",
    "readings": {
      "kind": "temperature",
      "value": 65
    }
  }
]
Try a fresh construction

This clears this draft, including its undo history. Earlier successful attempts stay recorded. Build again without opening hints to record an independent attempt.

Stuck? Inspect a worked construction

The tools below form one possible solution. You can assemble it, follow its signals, and undo that change to return to your own construction.

Assumptions and test precision

The browser runs an explicit model of the mechanism. It does not connect to MongoDB or Redis, simulate their query planners, or establish their concurrency guarantees. Numerical tests allow a difference of 0.001. Lists and structures must also have the right shape.

Your last tested pieces can start the full construction. An existing draft there keeps its own pieces.

Two qualifying readings still name one asset

This check uses the pieces from “Keep the reading member through both tests”.

BOTIE

P8 has two temperature readings at or above 80. P9 has an empty array. Return the parent identities at the requested grain.
Pump documents and readings
[
  {
    "asset_id": "P8",
    "readings": [
      {
        "kind": "temperature",
        "value": 80
      },
      {
        "kind": "temperature",
        "value": 91
      }
    ]
  },
  {
    "asset_id": "P9",
    "readings": []
  }
]
Requested reading kind
temperature
Minimum qualifying value
80

Use a number, text, or an array matching the requested result. For a matrix, put each row in brackets. Saving your prediction runs your current construction on these inputs and checks the earlier examples too.

Build a construction in the workspace above first. This case will test those pieces.

Why does the workshop remove duplicate asset records after filtering, rather than removing reading members first?

Decide the result grain, but retain the finer identity until its conditions have been checked.

The browser runs an explicit model of the mechanism. It does not connect to MongoDB or Redis, simulate their query planners, or establish their concurrency guarantees.

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