Database: social_media
Question: Tweets posted from which city has a higher number of average likes, Bangkok or Chiang Mai?
SQL: SELECT SUM(CASE WHEN T2.City = 'Bangkok' THEN Likes ELSE NULL END) / COUNT(CASE WHEN T2.City = 'Bangkok' THEN 1 ELSE 0 END) AS bNum , SUM(CASE WHEN City = 'Chiang Mai' THEN Likes ELSE NULL END) / COUNT(CASE WHEN City = 'Chiang Mai' THEN TweetID ELSE NULL END) AS cNum FROM twitter AS T1 INNER JOIN location AS T2 ON T1.LocationID = T2.LocationID WHERE T2.City IN ('Bangkok', 'Chiang Mai')