ElasticGraph Query API: Filtering

Use filter: on a root query field to narrow down the returned results:

query FindArtist {
  byName: artists(filter: {
    name: {equalToAnyOf: ["U2"]}
  }) {
    nodes {
      name
      bio {
        yearFormed
      }
    }
  }

  byBioYearFounded: artists(filter: {
    bio: {yearFormed: {gt: 2000}}
  }) {
    nodes {
      name
      bio {
        yearFormed
      }
    }
  }
}

As shown here, filters have two basic parts:

  • A field path: this specifies which field you want to filter on. When dealing with a nested field (e.g. bio.yearFormed), you’ll need to provide a nested object matching the field structure.
  • A filtering predicate: this specifies a filtering operator to apply at the field path.

Empty Filters

Filters with a value of null or empty object ({}) match all documents. When negated with not, no documents are matched. The filters in this query match all documents:

query EmptyFilters {
  artists(filter: {
    name: {equalToAnyOf: null}
    bio: {yearFormed: {}}
  }) {
    nodes {
      name
      bio {
        yearFormed
      }
    }
  }
}

This particularly comes in handy when using query variables. It allows a query to flexibly support a wide array of filters without requiring them to all be used for an individual request.

query FindArtists(
  $names: [String!] = null
  $yearFormed_gt: Int = null
  $albumNames: [String!] = null
) {
  artists(filter: {
    name: {equalToAnyOf: $names}
    bio: {yearFormed: {gt: $yearFormed_gt}}
    albums: {anySatisfy: {name: {equalToAnyOf: $albumNames}}}
  }) {
    nodes {
      name
      bio {
        yearFormed
      }
      albums {
        name
      }
    }
  }
}

Subpages