1 files changed, 5 insertions, 18 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
index ca8bbc14da..8b907759c6 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
@@ -63,7 +63,7 @@ module ActiveRecord
         /mariadb/i.match?(full_version)
       end
 
-      def supports_bulk_alter? #:nodoc:
+      def supports_bulk_alter?
         true
       end
 
@@ -285,22 +285,8 @@ module ActiveRecord
         SQL
       end
 
-      def bulk_change_table(table_name, operations) #:nodoc:
-        sqls = operations.flat_map do |command, args|
-          table, arguments = args.shift, args
-          method = :"#{command}_for_alter"
-
-          if respond_to?(method, true)
-            send(method, table, *arguments)
-          else
-            raise "Unknown method called : #{method}(#{arguments.inspect})"
-          end
-        end.join(", ")
-
-        execute("ALTER TABLE #{quote_table_name(table_name)} #{sqls}")
-      end
-
-      def change_table_comment(table_name, comment) #:nodoc:
+      def change_table_comment(table_name, comment_or_changes) # :nodoc:
+        comment = extract_new_comment_value(comment_or_changes)
         comment = "" if comment.nil?
         execute("ALTER TABLE #{quote_table_name(table_name)} COMMENT #{quote(comment)}")
       end
@@ -356,7 +342,8 @@ module ActiveRecord
         change_column table_name, column_name, nil, null: null
       end
 
-      def change_column_comment(table_name, column_name, comment) #:nodoc:
+      def change_column_comment(table_name, column_name, comment_or_changes) # :nodoc:
+        comment = extract_new_comment_value(comment_or_changes)
         change_column table_name, column_name, nil, comment: comment
       end