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

Inherits:

Object

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

show all

Extended by:: Protobuf::MessageExts::ClassMethods

Includes:: Protobuf::MessageExts

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

Overview

Defines an aggregation that produces a single result.

Defined Under Namespace

Classes: Count

Instance Attribute Summary collapse

#alias ⇒ ::String
Optional.
#count ⇒ ::Google::Cloud::Datastore::V1::AggregationQuery::Aggregation::Count
Count aggregator.

Instance Attribute Details

#alias ⇒ `::String`

Returns 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.

Returns:

(::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.

# File 'proto_docs/google/datastore/v1/query.rb', line 188

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
end

#count ⇒ `::Google::Cloud::Datastore::V1::AggregationQuery::Aggregation::Count`

Returns Count aggregator.