Add affected_rows to ActiveRecord::Result

For database adapters that do not support RETURNING, insert_all and
upsert_all does not provide what rows has been changed. Adding affected_rows to
the result allows this information to be accessed like other bulk operations
(like delete_all and update_all)

Author: jenshenny

activerecord/CHANGELOG.md

@@ -1,3 +1,7 @@
+*   Add `affected_rows` to `ActiveRecord::Result`.
+
+    *Jenny Shen*
+
 *   Enable passing retryable SqlLiterals to `#where`.
 
     *Hartley McGuire*

activerecord/lib/active_record/connection_adapters/mysql2/database_statements.rb

@@ -114,12 +114,12 @@ def perform_query(raw_connection, sql, binds, type_casted_binds, prepare:, notif
           end
 
           def cast_result(raw_result)
-            return ActiveRecord::Result.empty if raw_result.nil?
+            return ActiveRecord::Result.empty(affected_rows: @affected_rows_before_warnings) if raw_result.nil?
 
             fields = raw_result.fields
 
             result = if fields.empty?
-              ActiveRecord::Result.empty
+              ActiveRecord::Result.empty(affected_rows: @affected_rows_before_warnings)
             else
               ActiveRecord::Result.new(fields, raw_result.to_a)
             end

activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb

@@ -170,20 +170,20 @@ def perform_query(raw_connection, sql, binds, type_casted_binds, prepare:, notif
           end
 
           def cast_result(result)
-            if result.fields.empty?
-              result.clear
-              return ActiveRecord::Result.empty
-            end
+            ar_result = if result.fields.empty?
+              ActiveRecord::Result.empty(affected_rows: result.cmd_tuples)
+            else
+              fields = result.fields
+              types = Array.new(fields.size)
+              fields.size.times do |index|
+                ftype = result.ftype(index)
+                fmod  = result.fmod(index)
+                types[index] = get_oid_type(ftype, fmod, fields[index])
+              end
 
-            fields = result.fields
-            types = Array.new(fields.size)
-            fields.size.times do |index|
-              ftype = result.ftype(index)
-              fmod  = result.fmod(index)
-              types[index] = get_oid_type(ftype, fmod, fields[index])
+              ActiveRecord::Result.new(fields, result.values, types.freeze, affected_rows: result.cmd_tuples)
             end
 
-            ar_result = ActiveRecord::Result.new(fields, result.values, types.freeze)
             result.clear
             ar_result
           end

activerecord/lib/active_record/connection_adapters/sqlite3/database_statements.rb

@@ -88,35 +88,31 @@ def perform_query(raw_connection, sql, binds, type_casted_binds, prepare:, notif
 
             if batch
               raw_connection.execute_batch2(sql)
-            elsif prepare
-              stmt = @statements[sql] ||= raw_connection.prepare(sql)
-              stmt.reset!
-              stmt.bind_params(type_casted_binds)
-
-              result = if stmt.column_count.zero? # No return
-                stmt.step
-                ActiveRecord::Result.empty
+            else
+              stmt = if prepare
+                @statements[sql] ||= raw_connection.prepare(sql)
+                @statements[sql].reset!
               else
-                ActiveRecord::Result.new(stmt.columns, stmt.to_a, stmt.types.map { |t| type_map.lookup(t) })
+                # Don't cache statements if they are not prepared.
+                raw_connection.prepare(sql)
               end
-            else
-              # Don't cache statements if they are not prepared.
-              stmt = raw_connection.prepare(sql)
               begin
                 unless binds.nil? || binds.empty?
                   stmt.bind_params(type_casted_binds)
                 end
                 result = if stmt.column_count.zero? # No return
                   stmt.step
-                  ActiveRecord::Result.empty
+                  @affected_rows = raw_connection.total_changes - total_changes_before_query
+                  ActiveRecord::Result.empty(affected_rows: @affected_rows)
                 else
-                  ActiveRecord::Result.new(stmt.columns, stmt.to_a, stmt.types.map { |t| type_map.lookup(t) })
+                  rows = stmt.to_a
+                  @affected_rows = raw_connection.total_changes - total_changes_before_query
+                  ActiveRecord::Result.new(stmt.columns, rows, stmt.types.map { |t| type_map.lookup(t) }, affected_rows: @affected_rows)
                 end
               ensure
-                stmt.close
+                stmt.close unless prepare
               end
             end
-            @affected_rows = raw_connection.total_changes - total_changes_before_query
             verified!
 
             notification_payload[:affected_rows] = @affected_rows

activerecord/lib/active_record/connection_adapters/trilogy/database_statements.rb

@@ -41,9 +41,9 @@ def perform_query(raw_connection, sql, binds, type_casted_binds, prepare:, notif
 
           def cast_result(result)
             if result.fields.empty?
-              ActiveRecord::Result.empty
+              ActiveRecord::Result.empty(affected_rows: result.affected_rows)
             else
-              ActiveRecord::Result.new(result.fields, result.rows)
+              ActiveRecord::Result.new(result.fields, result.rows, affected_rows: result.affected_rows)
             end
           end
 

activerecord/lib/active_record/result.rb

@@ -29,6 +29,11 @@ module ActiveRecord
   #         ...
   #        ]
   #
+  #   # Get the number of rows affected by the query:
+  #   result = ActiveRecord::Base.lease_connection.exec_query('INSERT INTO posts (title, body) VALUES ("title_3", "body_3"), ("title_4", "body_4")')
+  #   result.affected_rows
+  #   # => 2
+  #
   #   # ActiveRecord::Result also includes Enumerable.
   #   result.each do |row|
   #     puts row['title'] + " " + row['body']
@@ -89,17 +94,17 @@ def to_h
       alias_method :to_hash, :to_h
     end
 
-    attr_reader :columns, :rows
+    attr_reader :columns, :rows, :affected_rows
 
-    def self.empty(async: false) # :nodoc:
+    def self.empty(async: false, affected_rows: nil) # :nodoc:
       if async
-        EMPTY_ASYNC
+        FutureResult.wrap(new(EMPTY_ARRAY, EMPTY_ARRAY, EMPTY_HASH, affected_rows: affected_rows)).freeze
       else
-        EMPTY
+        new(EMPTY_ARRAY, EMPTY_ARRAY, EMPTY_HASH, affected_rows: affected_rows).freeze
       end
     end
 
-    def initialize(columns, rows, column_types = nil)
+    def initialize(columns, rows, column_types = nil, affected_rows: nil)
       # We freeze the strings to prevent them getting duped when
       # used as keys in ActiveRecord::Base's @attributes hash
       @columns      = columns.each(&:-@).freeze
@@ -108,6 +113,7 @@ def initialize(columns, rows, column_types = nil)
       @column_types = column_types.freeze
       @types_hash   = nil
       @column_indexes = nil
+      @affected_rows = affected_rows
     end
 
     # Returns true if this result set includes the column named +name+
@@ -260,14 +266,8 @@ def hash_rows
         end
       end
 
-      empty_array = [].freeze
+      EMPTY_ARRAY = [].freeze
       EMPTY_HASH = {}.freeze
-      private_constant :EMPTY_HASH
-
-      EMPTY = new(empty_array, empty_array, EMPTY_HASH).freeze
-      private_constant :EMPTY
-
-      EMPTY_ASYNC = FutureResult.wrap(EMPTY).freeze
-      private_constant :EMPTY_ASYNC
+      private_constant :EMPTY_ARRAY, :EMPTY_HASH
   end
 end

activerecord/test/cases/adapter_test.rb

@@ -153,6 +153,23 @@ def test_current_database
       assert_not_empty result.columns
     end
 
+    test "#exec_query queries return an ActiveRecord::Result with affected rows" do
+      result = @connection.exec_query "INSERT INTO subscribers(nick, name) VALUES('me', 'me'), ('you', 'you')"
+      assert_equal 2, result.affected_rows
+
+      update_result = @connection.exec_query "UPDATE subscribers SET name = 'you' WHERE name = 'me'"
+      assert_equal 1, update_result.affected_rows
+
+      select_result = @connection.exec_query "SELECT * FROM subscribers"
+      assert_not_equal update_result.affected_rows, select_result.affected_rows
+
+      result = @connection.exec_query "DELETE FROM subscribers WHERE name = 'you'"
+      assert_equal 2, result.affected_rows
+
+      result = @connection.exec_query "DELETE FROM subscribers WHERE name = 'you'"
+      assert_equal 0, result.affected_rows
+    end
+
     if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
       def test_charset
         assert_not_nil @connection.charset

activerecord/test/cases/result_test.rb

@@ -9,7 +9,7 @@ def result
         ["row 1 col 1", "row 1 col 2"],
         ["row 2 col 1", "row 2 col 2"],
         ["row 3 col 1", "row 3 col 2"],
-      ])
+      ], affected_rows: 3)
     end
 
     test "includes_column?" do
@@ -138,6 +138,7 @@ def result
       assert_equal a.columns, b.columns
       assert_equal a.rows, b.rows
       assert_equal a.column_indexes, b.column_indexes
+      assert_equal a.affected_rows, b.affected_rows
 
       # Second round in case of mutation
       b = b.dup
@@ -146,6 +147,7 @@ def result
       assert_equal a.columns, b.columns
       assert_equal a.rows, b.rows
       assert_equal a.column_indexes, b.column_indexes
+      assert_equal a.affected_rows, b.affected_rows
     end
 
     test "column_types handles nil types in the column_types array" do