Question

I have a repeating field A which contains a list of strings. what would be a good way to find TOP strings which coincide with a given string. So, if A holds hashtags, for a given hashtag #T1, find the tags that coincide with #T1 in highest number of records.

Answer 1

You can use WITHIN and SUM(IF(...)) to find the matches. For example:

SELECT hashtag, COUNT(*) AS cnt
    (SELECT tweet.hashtag as hashtag, 
            SUM(IF(tweet.hashtag == '#T1', 1, 0)) WITHIN RECORD as tagz
     FROM [tweets]) 
WHERE tagz  > 0
GROUP by hashtag,
ORDER BY cnt DESC