aggregate_query.rb in google-cloud-datastore-2.8.0

- old
+ new

@@ -54,10 +54,19 @@
       #
       #   aggregate_query_results = dataset.run_aggregation aggregate_query
       #   puts aggregate_query_results.get('total')
       #
       class AggregateQuery
+        # @private
+        DEFAULT_COUNT_AGGREGATE_ALIAS = "count".freeze
+
+        # @private
+        DEFAULT_SUM_AGGREGATE_ALIAS = "sum".freeze
+
+        # @private
+        DEFAULT_AVG_AGGREGATE_ALIAS = "avg".freeze
+
         ##
         # @private The Google::Cloud::Datastore::V1::AggregationQuery object.
         attr_reader :grpc
 
         ##
@@ -111,28 +120,130 @@
         #
         #   aggregate_query_results = dataset.run_aggregation aggregate_query
         #   puts aggregate_query_results.get('total')
         #
         def add_count aggregate_alias: nil
-          aggregate_alias ||= ALIASES[:count]
+          aggregate_alias ||= DEFAULT_COUNT_AGGREGATE_ALIAS
           @grpc.aggregations << Google::Cloud::Datastore::V1::AggregationQuery::Aggregation.new(
             count: Google::Cloud::Datastore::V1::AggregationQuery::Aggregation::Count.new,
             alias: aggregate_alias
           )
 
           self
         end
 
-        # @private
-        def to_grpc
-          @grpc
+        ##
+        # Adds a sum aggregate.
+        #
+        # @param name [String] The property to sum by.
+        # @param aggregate_alias [String] Alias to refer to the aggregate. Optional
+        #
+        # @return [AggregateQuery] The modified aggregate query object with the added SUM aggregate.
+        #
+        # @example
+        #   require "google/cloud/datastore"
+        #
+        #   datastore = Google::Cloud::Datastore.new
+        #
+        #   query = Google::Cloud::Datastore::Query.new
+        #   query.kind("Task")
+        #        .where("done", "=", false)
+        #
+        #   Create an aggregate query
+        #   aggregate_query = query.aggregate_query
+        #                          .add_sum("score")
+        #
+        #   aggregate_query_results = dataset.run_aggregation aggregate_query
+        #   puts aggregate_query_results.get
+        #
+        # @example Alias an aggregate SUM query
+        #   require "google/cloud/datastore"
+        #
+        #   datastore = Google::Cloud::Datastore.new
+        #
+        #   query = Google::Cloud::Datastore::Query.new
+        #   query.kind("Task")
+        #        .where("done", "=", false)
+        #
+        #   # Create an aggregate query
+        #   aggregate_query = query.aggregate_query
+        #                          .add_sum("score", aggregate_alias: 'total_score')
+        #
+        #   aggregate_query_results = dataset.run_aggregation aggregate_query
+        #   puts aggregate_query_results.get('total_score')
+        #
+        def add_sum name, aggregate_alias: nil
+          aggregate_alias ||= DEFAULT_SUM_AGGREGATE_ALIAS
+          @grpc.aggregations << Google::Cloud::Datastore::V1::AggregationQuery::Aggregation.new(
+            sum: Google::Cloud::Datastore::V1::AggregationQuery::Aggregation::Sum.new(
+              property: Google::Cloud::Datastore::V1::PropertyReference.new(
+                name: name
+              )
+            ),
+            alias: aggregate_alias
+          )
+
+          self
         end
 
         ##
+        # Adds an average aggregate.
+        #
+        # @param name [String] The property to apply average on.
+        # @param aggregate_alias [String] Alias to refer to the aggregate. Optional
+        #
+        # @return [AggregateQuery] The modified aggregate query object with the added AVG aggregate.
+        #
+        # @example
+        #   require "google/cloud/datastore"
+        #
+        #   datastore = Google::Cloud::Datastore.new
+        #
+        #   query = Google::Cloud::Datastore::Query.new
+        #   query.kind("Task")
+        #        .where("done", "=", false)
+        #
+        #   Create an aggregate query
+        #   aggregate_query = query.aggregate_query
+        #                          .add_avg("score")
+        #
+        #   aggregate_query_results = dataset.run_aggregation aggregate_query
+        #   puts aggregate_query_results.get
+        #
+        # @example Alias an aggregate AVG query
+        #   require "google/cloud/datastore"
+        #
+        #   datastore = Google::Cloud::Datastore.new
+        #
+        #   query = Google::Cloud::Datastore::Query.new
+        #   query.kind("Task")
+        #        .where("done", "=", false)
+        #
+        #   # Create an aggregate query
+        #   aggregate_query = query.aggregate_query
+        #                          .add_avg("score", aggregate_alias: 'avg_score')
+        #
+        #   aggregate_query_results = dataset.run_aggregation aggregate_query
+        #   puts aggregate_query_results.get('avg_score')
+        #
+        def add_avg name, aggregate_alias: nil
+          aggregate_alias ||= DEFAULT_AVG_AGGREGATE_ALIAS
+          @grpc.aggregations << Google::Cloud::Datastore::V1::AggregationQuery::Aggregation.new(
+            avg: Google::Cloud::Datastore::V1::AggregationQuery::Aggregation::Avg.new(
+              property: Google::Cloud::Datastore::V1::PropertyReference.new(
+                name: name
+              )
+            ),
+            alias: aggregate_alias
+          )
+
+          self
+        end
+
         # @private
-        ALIASES = {
-          count: "count"
-        }.freeze
+        def to_grpc
+          @grpc
+        end
       end
     end
   end
 end