Class: Google::Cloud::Datastore::V1::AggregationQuery

Inherits:

Object

Object
Google::Cloud::Datastore::V1::AggregationQuery

show all

Extended by:: Protobuf::MessageExts::ClassMethods

Includes:: Protobuf::MessageExts

Defined in:: proto_docs/google/datastore/v1/query.rb

Overview

Datastore query for running an aggregation over a Query.

Defined Under Namespace

Classes: Aggregation

Instance Attribute Summary collapse

#aggregations ⇒ ::Array<::Google::Cloud::Datastore::V1::AggregationQuery::Aggregation>
Optional.
#nested_query ⇒ ::Google::Cloud::Datastore::V1::Query
Nested query for aggregation.

Instance Attribute Details

#aggregations ⇒ `::Array<::Google::Cloud::Datastore::V1::AggregationQuery::Aggregation>`

Returns Optional. Series of aggregations to apply over the results of the nested_query.

Requires:

A minimum of one and maximum of five aggregations per query.

Returns:

(::Array<::Google::Cloud::Datastore::V1::AggregationQuery::Aggregation>) —
Optional. Series of aggregations to apply over the results of the nested_query.

Requires:
- A minimum of one and maximum of five aggregations per query.

# File 'proto_docs/google/datastore/v1/query.rb', line 159

class AggregationQuery
  include ::Google::Protobuf::MessageExts
  extend ::Google::Protobuf::MessageExts::ClassMethods

  # Defines an aggregation that produces a single result.
  # @!attribute [rw] count
  #   @return [::Google::Cloud::Datastore::V1::AggregationQuery::Aggregation::Count]
  #     Count aggregator.
  # @!attribute [rw] sum
  #   @return [::Google::Cloud::Datastore::V1::AggregationQuery::Aggregation::Sum]
  #     Sum aggregator.
  # @!attribute [rw] avg
  #   @return [::Google::Cloud::Datastore::V1::AggregationQuery::Aggregation::Avg]
  #     Average aggregator.
  # @!attribute [rw] alias
  #   @return [::String]
  #     Optional. Optional name of the property to store the result of the
  #     aggregation.
  #
  #     If not provided, Datastore will pick a default name following the format
  #     `property_<incremental_id++>`. For example:
  #
  #     ```
  #     AGGREGATE
  #       COUNT_UP_TO(1) AS count_up_to_1,
  #       COUNT_UP_TO(2),
  #       COUNT_UP_TO(3) AS count_up_to_3,
  #       COUNT(*)
  #     OVER (
  #       ...
  #     );
  #     ```
  #
  #     becomes:
  #
  #     ```
  #     AGGREGATE
  #       COUNT_UP_TO(1) AS count_up_to_1,
  #       COUNT_UP_TO(2) AS property_1,
  #       COUNT_UP_TO(3) AS count_up_to_3,
  #       COUNT(*) AS property_2
  #     OVER (
  #       ...
  #     );
  #     ```
  #
  #     Requires:
  #
  #     * Must be unique across all aggregation aliases.
  #     * Conform to [entity property
  #     name][google.datastore.v1.Entity.properties] limitations.
  class Aggregation
    include ::Google::Protobuf::MessageExts
    extend ::Google::Protobuf::MessageExts::ClassMethods

    # Count of entities that match the query.
    #
    # The `COUNT(*)` aggregation function operates on the entire entity
    # so it does not require a field reference.
    # @!attribute [rw] up_to
    #   @return [::Google::Protobuf::Int64Value]
    #     Optional. Optional constraint on the maximum number of entities to
    #     count.
    #
    #     This provides a way to set an upper bound on the number of entities
    #     to scan, limiting latency, and cost.
    #
    #     Unspecified is interpreted as no bound.
    #
    #     If a zero value is provided, a count result of zero should always be
    #     expected.
    #
    #     High-Level Example:
    #
    #     ```
    #     AGGREGATE COUNT_UP_TO(1000) OVER ( SELECT * FROM k );
    #     ```
    #
    #     Requires:
    #
    #     * Must be non-negative when present.
    class Count
      include ::Google::Protobuf::MessageExts
      extend ::Google::Protobuf::MessageExts::ClassMethods
    end

    # Sum of the values of the requested property.
    #
    # * Only numeric values will be aggregated. All non-numeric values
    # including `NULL` are skipped.
    #
    # * If the aggregated values contain `NaN`, returns `NaN`. Infinity math
    # follows IEEE-754 standards.
    #
    # * If the aggregated value set is empty, returns 0.
    #
    # * Returns a 64-bit integer if all aggregated numbers are integers and the
    # sum result does not overflow. Otherwise, the result is returned as a
    # double. Note that even if all the aggregated values are integers, the
    # result is returned as a double if it cannot fit within a 64-bit signed
    # integer. When this occurs, the returned value will lose precision.
    #
    # * When underflow occurs, floating-point aggregation is non-deterministic.
    # This means that running the same query repeatedly without any changes to
    # the underlying values could produce slightly different results each
    # time. In those cases, values should be stored as integers over
    # floating-point numbers.
    # @!attribute [rw] property
    #   @return [::Google::Cloud::Datastore::V1::PropertyReference]
    #     The property to aggregate on.
    class Sum
      include ::Google::Protobuf::MessageExts
      extend ::Google::Protobuf::MessageExts::ClassMethods
    end

    # Average of the values of the requested property.
    #
    # * Only numeric values will be aggregated. All non-numeric values
    # including `NULL` are skipped.
    #
    # * If the aggregated values contain `NaN`, returns `NaN`. Infinity math
    # follows IEEE-754 standards.
    #
    # * If the aggregated value set is empty, returns `NULL`.
    #
    # * Always returns the result as a double.
    # @!attribute [rw] property
    #   @return [::Google::Cloud::Datastore::V1::PropertyReference]
    #     The property to aggregate on.
    class Avg
      include ::Google::Protobuf::MessageExts
      extend ::Google::Protobuf::MessageExts::ClassMethods
    end
  end
end

#nested_query ⇒ `::Google::Cloud::Datastore::V1::Query`

Returns Nested query for aggregation.