Related section

Using a readingsFilter in the related section of a $findWithRelated query

Insert a readingsFilter in the related section of a $findWithRelated query to return the related items, such as HVAC air handling units, in a collection that have a relationship to telemetry items whose readings match your query.

Structure your $findWithRelated query as follows:

{
  "$findWithRelated": {
    "parent": {
      "collectionDesc": {
        "<property to identify a collection you want to query. In this example, an asset collection>": "<identifying value>"
      },
      "query": {
        //<simple query to find matching related items in the collection. 
        //In this example we want to find HVAC air handling units>            
      },
    },
    "related": [
      {
        "relatedDesc": {
          "<property to identify the telemetry collection you want>": "<value>"
        },
        "readingsFilter": {
          "query": {
            //<Valid simple telemetry reading query to filter parent 
            //related items, in this example, HVAC air handling units> 
          },
        }
        "as": "sensor",
      }
    ]
  }
}

The following code example returns a list of HVAC units whose sensors recorded a temperature above 11℃ on or after 09:00, December 1st, 2021:

Example request

{
  "$findWithRelated": {
    "parent": {
      "query": {
        "properties.dtCategory.val": "HVAC Air Handling Unit"
      },
      "collectionDesc": {
        "_userItemId": "asset_coll_jPQCU4n096"
      }
    },
    "related": [
      {
        "relatedDesc": {
          "_relatedUserType": "iaf_telemetry_timeseries"
        },
        "readingsFilter": {
          "query": {
            "$and": [
              {
                "temp": {
                  "$gte": 10
                }
              }
            ]
          }
        },
        "as": "sensor"
      }
    ]
  }
}

Example response

{
  "_list": [
    {
      "_uri": "/nameduseritems/634cd7e89d34dd31017382e0",
      "_name": "Building assets Collection",
      "_userType": "iaf_ext_asset_coll",
      "_tipId": "634cd7e89d34dd31017382e1",
      "_versions": [
        {
          "_userItemDbId": "634cd7e89d34dd31017382e0",
          "_relatedItems": {
            "_pageSize": 3,
            "_list": [
              {
                "Asset Name": "5SPD.R1.HV.AHU.0002",
                "sensor": {
                  "_pageSize": 1,
                  "_list": [
                    {
                      "_sourceId": "e3e052f9-0156-11d5-9301-0000863f27ad-00000131",
                      "_id": "634ce4999d34dd31017382ef",
                      "_metadata": {
                        "_updatedById": "057ce6fd-a306-4bdc-8514-0a45c453f7ec",
                        "_createdAt": 1665983641162,
                        "_createdById": "057ce6fd-a306-4bdc-8514-0a45c453f7ec",
                        "_updatedAt": 1665983641162
                      }
                    }
                  ],
                  "_offset": 0,
                  "_total": 1
                },
                "_id": "634ce4769d34dd31017382ed",
                "_metadata": {
                  "_updatedById": "057ce6fd-a306-4bdc-8514-0a45c453f7ec",
                  "_createdAt": 1665983606783,
                  "_createdById": "057ce6fd-a306-4bdc-8514-0a45c453f7ec",
                  "_updatedAt": 1665983606783
                },
                "properties": {
                  "dtCategory": {
                    "val": "HVAC Air Handling Unit"
                  },
                  "Containing Floor": {
                    "val": 1
                  }
                }
              },
              {
                "Asset Name": "5SPD.R1.HV.AHU.0003",
                "sensor": {
                  "_pageSize": 1,
                  "_list": [
                    {
                      "_sourceId": "a54052f9-0156-11d5-9301-0000863f27ad-000001454",
                      "_id": "634ce4999d34dd31017382f0",
                      "_metadata": {
                        "_updatedById": "057ce6fd-a306-4bdc-8514-0a45c453f7ec",
                        "_createdAt": 1665983641163,
                        "_createdById": "057ce6fd-a306-4bdc-8514-0a45c453f7ec",
                        "_updatedAt": 1665983641163
                      }
                    }
                  ],
                  "_offset": 0,
                  "_total": 1
                },
                "_id": "634ce4769d34dd31017382ee",
                "_metadata": {
                  "_updatedById": "057ce6fd-a306-4bdc-8514-0a45c453f7ec",
                  "_createdAt": 1665983606783,
                  "_createdById": "057ce6fd-a306-4bdc-8514-0a45c453f7ec",
                  "_updatedAt": 1665983606783
                },
                "properties": {
                  "dtCategory": {
                    "val": "HVAC Air Handling Unit"
                  },
                  "Containing Floor": {
                    "val": 2
                  }
                }
              },
              {
                "Asset Name": "5SPD.R1.HV.AHU.0004",
                "sensor": {
                  "_pageSize": 0,
                  "_list": [],
                  "_offset": 0,
                  "_total": 0
                },
                "_id": "634ce6ac9d34dd31017382f7",
                "_metadata": {
                  "_updatedById": "057ce6fd-a306-4bdc-8514-0a45c453f7ec",
                  "_createdAt": 1665984172343,
                  "_createdById": "057ce6fd-a306-4bdc-8514-0a45c453f7ec",
                 "_updatedAt": 1665984172343
                },
                "properties": {
                  "dtCategory": {
                    "val": "HVAC Air Handling Unit"
                  },
                  "Containing Floor": {
                    "val": 3
                  }
                }
              }
            ],
            "_offset": 0,
            "_total": 3
          },
          "_id": "634cd7e89d34dd31017382e1",
          "_isTip": true,
          "_metadata": {
            "_updatedById": "057ce6fd-a306-4bdc-8514-0a45c453f7ec",
            "_createdAt": 1665980392076,
            "_createdById": "057ce6fd-a306-4bdc-8514-0a45c453f7ec",
            "_updatedAt": 1665980392076
          },
          "_version": 1
        }
      ],
      "_irn": "itemsvc:nameduseritem:634cd7e89d34dd31017382e0",
      "_namespaces": [
        "Lnt_GglJp74V"
      ],
      "_nextVersion": 2,
      "_shortName": "asset_coll",
      "_tipVersion": 1,
      "_versionsCount": 1,
      "_itemClass": "NamedUserCollection",
      "_userItemId": "asset_coll_jPQCU4n096",
      "_id": "634cd7e89d34dd31017382e0",
      "_metadata": {
        "_updatedById": "057ce6fd-a306-4bdc-8514-0a45c453f7ec",
        "_createdAt": 1665980392072,
        "_createdById": "057ce6fd-a306-4bdc-8514-0a45c453f7ec",
        "_updatedAt": 1665980392072
      },
      "_kind": "collection"
    }
  ],
  "_time": "62ms"
}