What is the earliest sunrise recorded in the stations with no more than 1 store in February 2012?
in February 2012 refers to SUBSTR(date, 1, 7) = '2012-02'; earliest sunrise Min(sunrise);  station with no more than 1 store refers to station_nbr where Count(store_nbr) = 1
SELECT T1.station_nbr FROM relation AS T1 INNER JOIN weather AS T2 ON T1.station_nbr = T2.station_nbr WHERE sunrise IS NOT NULL AND T2.`date` LIKE '%2012-02%' AND T1.station_nbr IN ( SELECT station_nbr FROM relation GROUP BY station_nbr HAVING COUNT(store_nbr) = 1 ) ORDER BY sunrise LIMIT 1