1 files changed, 25 insertions, 14 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb b/activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb
index 6f2e03b370..7414eba6c5 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb
@@ -4,7 +4,7 @@ module ActiveRecord
       module DatabaseStatements
         def explain(arel, binds = [])
           sql = "EXPLAIN #{to_sql(arel, binds)}"
-          PostgreSQL::ExplainPrettyPrinter.new.pp(exec_query(sql, 'EXPLAIN', binds))
+          PostgreSQL::ExplainPrettyPrinter.new.pp(exec_query(sql, "EXPLAIN", binds))
         end
 
         def select_value(arel, name = nil, binds = [])
@@ -74,9 +74,9 @@ module ActiveRecord
               #  (2) $12.345.678,12
               case data
               when /^-?\D+[\d,]+\.\d{2}$/  # (1)
-                data.gsub!(/[^-\d.]/, '')
+                data.gsub!(/[^-\d.]/, "")
               when /^-?\D+[\d.]+,\d{2}$/  # (2)
-                data.gsub!(/[^-\d,]/, '').sub!(/,/, '.')
+                data.gsub!(/[^-\d,]/, "").sub!(/,/, ".")
               end
             end
           end
@@ -99,7 +99,7 @@ module ActiveRecord
           end
         end
 
-        def exec_query(sql, name = 'SQL', binds = [], prepare: false)
+        def exec_query(sql, name = "SQL", binds = [], prepare: false)
           execute_and_clear(sql, name, binds, prepare: prepare) do |result|
             types = {}
             fields = result.fields
@@ -112,8 +112,8 @@ module ActiveRecord
           end
         end
 
-        def exec_delete(sql, name = 'SQL', binds = [])
-          execute_and_clear(sql, name, binds) {|result| result.cmd_tuples }
+        def exec_delete(sql, name = nil, binds = [])
+          execute_and_clear(sql, name, binds) { |result| result.cmd_tuples }
         end
         alias :exec_update :exec_delete
 
@@ -124,24 +124,29 @@ module ActiveRecord
             pk = primary_key(table_ref) if table_ref
           end
 
-          if pk && use_insert_returning?
+          if pk = suppress_composite_primary_key(pk)
             sql = "#{sql} RETURNING #{quote_column_name(pk)}"
           end
 
           super
         end
+        protected :sql_for_insert
 
-        def exec_insert(sql, name, binds, pk = nil, sequence_name = nil)
-          val = exec_query(sql, name, binds)
-          if !use_insert_returning? && pk
+        def exec_insert(sql, name = nil, binds = [], pk = nil, sequence_name = nil)
+          if use_insert_returning? || pk == false
+            super
+          else
+            result = exec_query(sql, name, binds)
             unless sequence_name
               table_ref = extract_table_ref_from_insert_sql(sql)
-              sequence_name = default_sequence_name(table_ref, pk)
-              return val unless sequence_name
+              if table_ref
+                pk = primary_key(table_ref) if pk.nil?
+                pk = suppress_composite_primary_key(pk)
+                sequence_name = default_sequence_name(table_ref, pk)
+              end
+              return result unless sequence_name
             end
             last_insert_id_result(sequence_name)
-          else
-            val
           end
         end
 
@@ -164,6 +169,12 @@ module ActiveRecord
         def exec_rollback_db_transaction
           execute "ROLLBACK"
         end
+
+        private
+
+          def suppress_composite_primary_key(pk)
+            pk unless pk.is_a?(Array)
+          end
       end
     end
   end