OPEN c1;
    city_loop: LOOP
    FETCH c1 into s_CC,s_REG;
    set t1= concat('\'',concat(s_CC,'\''));
    SET s_countrycode = concat_WS(',',s_countrycode,t1);

   IF l_done=1 THEN
       LEAVE city_loop;
    END IF;
  END LOOP city_loop;

  SET @LOC = s_countrycode;
  SET @SQL ='SELECT * from city where countrycode IN (';
  SET @SQL = concat(concat(@SQL,@LOC),') AND  city.population >  10000 AND city.population < 500000 ');
  PREPARE s1 FROM @SQL;
  EXECUTE s1;
  CLOSE c1;