Question

i have an question how to use an “alias” column at the where/having clause. I know there are some question with an related topic. But I search trough the web and on stackoverfolw and doesn’t find an solution.

So i hope for help at this way..

The following statement works well:

SELECT PHRASE,COUNT(*) AS A 
    FROM my_statistics 
    WHERE TIMESTAMP>NOW()-INTERVAL 7 DAY
    GROUP BY PHRASE ORDER BY A DESC 
    LIMIT 16;

PHRASE and TIMESTAMPare columns at the table.
The code selects the top 16 PHRASES, which are inserts by users on the last 7 days.
There are also exist an column USER and so i like now to select the top 16 phrases which are inserted by more than one user.
So i tried this:

SELECT PHRASE,COUNT(*) AS A, COUNT(DISTINCT(USER)) AS B
    FROM my_statistics
    WHERE TIMESTAMP>NOW()-INTERVAL 7 DAY
          AND B>1
    GROUP BY PHRASE ORDER BY A DESC 
    LIMIT 16;

On other questions on stackoverflow i fond the info, that i have to use HAVING

SELECT PHRASE,COUNT(*) AS A, COUNT(DISTINCT(USER)) AS B
    FROM my_statistics
    WHERE TIMESTAMP>NOW()-INTERVAL 7 DAY      
    GROUP BY PHRASE ORDER BY A DESC 
    HAVING B>1
    LIMIT 16;

But this returns an error:

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ‘HAVING B>1
LIMIT 16’ at line 5

I have no idea, how the right syntax could be.
Hope for any kind of help here.
Thank you!

Answer 1

Place the ORDER BY A DESC after Having clause.

SELECT phrase, 
       Count(*)                AS A, 
       Count(DISTINCT( user )) AS B 
FROM   my_statistics 
WHERE  timestamp > Now() - INTERVAL 7 day 
GROUP  BY phrase 
HAVING b > 1 
ORDER  BY a DESC 
LIMIT  16;