def to_unprepared_sql
          if self.connection.respond_to?(:unprepared_statement)
            self.connection.unprepared_statement do
              to_sql
            end
          else
            to_sql
          end
        end
Returns sql string like #to_sql, but with bind parameters interpolated.
ActiveRecord sets up query as prepared statements with bind variables.
Cursors will prepare statements regardless.