GraphQL queries

You can query the instances with GraphQL. The query capabilities of the GraphQL API interface represent a subset of the capabilities available from the DMS query endpoints.

A query has these key sections:

• A query intent query MyQueryName { (or just { as shorthand).

• The query to run. This can be one of four types of queries (with an optional alias, for example, myAlias: listActor):

  • list<type>, for example, listActor lists based on filter parameters.

  • get<type>ById, for example, getActorById lists based on filter parameters.

  • search<type>, for example, searchActor searches based on a query parameter.

  • aggregate<type>, for example, aggregateActor aggregates (count, average etc.) based on a field.

    See the query types section for more details.

• The query parameters. For example, filter: {...} or limit: 1000.

• The properties to return at a specified depth.

GraphQL example

query myQuery {
  listCountry {
    items {
      name
      demographics {
        populationSize
        growthRate
      }
      deaths {
        datapoints(limit: 100) {
          timestamp
          value
        }
      }
    }
    nextCursor
  }
  listDemographics(
    filter: {
      _and: [{ populationSize: { gte: 2 } }, { populationSize: { lte: 10 } }]
    }
  ) {
    items {
      populationSize
      growthRate
      metadata {
        key
        value
      }
    }
  }
}

Where:

• myQuery declares the query intent.
• listCountry and listDemographics are the queries to run.
• The parameters are Country:100 for the deaths time series data points, and the Demographics: filter of populationSize between 2 and 10.
• The properties to return, for Country: items -> name, demographic -> populationSize, growthRate, etc.

For more information, see the GraphQL documentation.

Query types

list queries

list<type> lets you filter and sort data quickly. For list<type> you can use these properties and parameters:

• Properties

  • items: specify the properties to return data for
  • pageInfo: details about the current set of returned items. The existence of endCursor indicates that there is another page of data.

• Parameters

  • filter: the filter you want to use based on the properties in your graph. You can use and, or, and not operators to create complex queries.
  • sort: the ordering of the returned data you want. Specify an array of one or more properties to sort the data of, and whether their data should be sorted in ASC or DESC order.
  • after: where in the result set to continue from, using the endCursor value from the previous query.
  • first: the maximum number of items to return. To fetch more items use a new query, and supply the value from the previous query's endCursor parameter. (Default maximum: 1000 instances)

Pagination

Pagination is only supported at the top level when using list<type> queries.

For a query like the one below, cursors will only be returned to paginate through the data returned from Movies, but not from Actors. If you need to paginate through nested types, for actors in this example, use the get<type>ById queries instead:

query ListMovies {
  listMovie {
    items {
      title
      actors {
        name
      }
    }
    pageInfo {
      endCursor
    }
  }
}

getById queries

Use get<type>ById to fetch a specific item by its externalId. For get<type>ById, you can use similar properties and parameters as list queries. Pagination for nested items is available when using get<type>ById.

• Properties

  • items: specify which properties to return.

search queries

Use search<type> to search and query data quickly. For search<type> you can use these properties and parameters:

• Properties - The same as for the list queries.

• Parameters

  • filter: the filter you want to provide based on the properties in your data model. You can use an array of and, or, and not to create more complex queries.
  • fields: the properties you want to search on. This can be an array of properties.
  • query: the actual search queries. Wildcards are supported.
  • first: the maximum number of items to return. To fetch more items, use a new query using the endCursor parameter.(Default: 1000)

aggregate queries

Use aggregate<type> to aggregate data and compute rollups on the instances in a type. For aggregate<type>, you can use these properties and parameters:

• Properties

  • group: depending on the groupBy parameter, this indicates the group. The group is the name of each aggregation bucket based on the value(s) of the field(s) used in the groupBy parameter.
  • avg: for number properties, you can ask for the average.
  • count: for any type of properties, you can ask for the total count.
  • histogram(interval: <number>): for number properties, you can ask for the histogram for an interval.
  • max: for number properties, you can ask for the maximum value.
  • min: for number properties, you can ask for the minimum value.
  • sum: for number properties, you can ask for the total sum.
  • pageInfo: the details about the current set of returned items. The existence of endCursor indicates that there is another page of data.

• Parameters

  • filter: perform the aggregation on instances matching a logical expression. This filter is applied to the fields in your data type as described below, and you can use an array of and, or, and not to create more complex queries. For text field searches other than prefix matching, use query.
  • query: applies a full-text search to text fields in the type and performs the aggregation on instances matching the query and filter. The query is, by default, applied to all text fields in the type, but can be constrained to a subset of the fields using the fields parameter.
  • fields: the properties or fields you want to search in with the query search. This can be an array of fields.
  • groupBy: the field(s) to group by (no relationship allowed).
  • after: the nextCursor from the previous query, for pagination.

Filter specifications

	Field	Filter	How to use
Top level filters	Any	and	{and: [{...},{...}]} = if everything is true.
		or	{or: [{...},{...}]} = if at least one is true.
		not	{not: {...}} = if false.
Primitives	Any	eq	{eq: ...}
		in	{in: ["..."]} = if any of term.
	Nullable	isNull	{isNull: True} = if the field is empty.
	String	prefix	{prefix: "..."} = starts with.
	Int/Int64/Float/Timestamp	lt	{lt: ...} = less than.
		gt	{gt: ...} = greater than.
		lte	{lte: ...} = less than or equals.
		gte	{gte: ...} = greater than or equals.
	TimeSeries	❌	Not supported.
User defined type		❌	Not supported.
Lists([XXX])		❌	Not supported.

Unit conversion

Fields that are enabled for unit conversion will contain targetUnit and targetUnitSystem attributes.

• targetUnit: specifies the external ID of the unit that the retrieved data will be converted to.
• targetUnitSystem: specifies the unit by the unit system the retrieved data will be converted to.

See developer.cognite.com for more information and examples.

Unit information

unitInfo object contains unit information, unitExternalId, sourceUnit for unit enabled fields. See developer.cognite.com for more information and examples.