table_name_matches?

# File activerecord/lib/active_record/relation/query_methods.rb, line 1808
      def table_name_matches?(from)
        table_name = Regexp.escape(table.name)
        quoted_table_name = Regexp.escape(connection.quote_table_name(table.name))
        /(?:\A|(?<!FROM)\s)(?:\b#{table_name}\b|#{quoted_table_name})(?!\.)/.match?(from.to_s)
      end