Prevent `table_comment` query if a table doesn't have a comment

3 files changed, 17 insertions, 7 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 718a6c5b91..41c6b2d9bd 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
@@ -542,7 +542,9 @@ module ActiveRecord
         end
       end
 
-      def table_options(table_name)
+      def table_options(table_name) # :nodoc:
+        table_options = {}
+
         create_table_info = create_table_info(table_name)
 
         # strip create_definitions and partition_options
@@ -551,10 +553,14 @@ module ActiveRecord
         # strip AUTO_INCREMENT
         raw_table_options.sub!(/(ENGINE=\w+)(?: AUTO_INCREMENT=\d+)/, '\1')
 
+        table_options[:options] = raw_table_options
+
         # strip COMMENT
-        raw_table_options.sub!(/ COMMENT='.+'/, '')
+        if raw_table_options.sub!(/ COMMENT='.+'/, '')
+          table_options[:comment] = table_comment(table_name)
+        end
 
-        raw_table_options
+        table_options
       end
 
       # Maps logical Rails types to MySQL-specific data types.
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
index 6318b1c65a..4a7a166e5b 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
@@ -238,6 +238,10 @@ module ActiveRecord
           PostgreSQLColumn.new(*args)
         end
 
+        def table_options(table_name) # :nodoc:
+          { comment: table_comment(table_name) }
+        end
+
         # Returns a comment stored in database for given table
         def table_comment(table_name) # :nodoc:
           name = Utils.extract_schema_qualified_name(table_name.to_s)
diff --git a/activerecord/lib/active_record/schema_dumper.rb b/activerecord/lib/active_record/schema_dumper.rb
index d769376d1a..1813bcd26a 100644
--- a/activerecord/lib/active_record/schema_dumper.rb
+++ b/activerecord/lib/active_record/schema_dumper.rb
@@ -132,10 +132,10 @@ HEADER
           tbl.print ", force: :cascade"
 
           table_options = @connection.table_options(table)
-          tbl.print ", options: #{table_options.inspect}" unless table_options.blank?
-
-          if comment = @connection.table_comment(table).presence
-            tbl.print ", comment: #{comment.inspect}"
+          if table_options.present?
+            table_options.each do |key, value|
+              tbl.print ", #{key}: #{value.inspect}" if value.present?
+            end
           end
 
           tbl.puts " do |t|"