Question

query the two cities in station with the shortest and longest city names as well as their respective lengths (i.e.: number of characters in the name). if there is more than one smallest or largest city choose the one that comes first when ordered alphabetically.

Answer 1

( select CITY,  

      char_length(CITY) as len_city  

 from STATION  

 where char_length(CITY)=(select char_length(CITY)  

                         from STATION  

                         order by char_length(CITY) LIMIT 1)  

 Order by CITY LIMIT 1)  

UNION ALL  

(select CITY,

       char_length(CITY) as len_city  

 from STATION  

 where char_length(CITY)=(select char_length(CITY)  

                          from STATION  

                          order by char_length(CITY) DESC LIMIT 1)  

 Order by CITY DESC LIMIT 1)  

 ORDER BY char_length(CITY);