Working with INTERVAL and CURDATE in MySQL

Question

I'm building a chart and I want to receive data for each month.

Here's my first request which is working:

SELECT s.GSP_nom AS nom, timestamp, AVG( v.vote +  v.prix  ) /2 AS avg FROM votes_serveur AS v INNER JOIN serveur AS s ON v.idServ = s.idServ WHERE s.valide =1 AND v.date > CURDATE() -30 GROUP BY s.GSP_nom ORDER BY avg DESC 

But, in my case I've to write 12 request to receive data for the 12 previous months, is there any trick to avoid writing:

//  example for the previous month  AND v.date > CURDATE() -60 AND v.date < CURDATE () -30 

I heard about INTERVAL, I went to the MySQL doc but i didn't manage to implement it.

Any example of using INTERVAL please?

Answer 1

You need DATE_ADD/DATE_SUB:

AND v.date > (DATE_SUB(CURDATE(), INTERVAL 2 MONTH)) AND v.date < (DATE_SUB(CURDATE(), INTERVAL 1 MONTH)) 

should work.

Answer 2

As suggested by A Star, I always use something along the lines of:

DATE(NOW()) - INTERVAL 1 MONTH 

Similarly you can do:

NOW() + INTERVAL 5 MINUTE "2013-01-01 00:00:00" + INTERVAL 10 DAY 

and so on. Much easier than typing DATE_ADD or DATE_SUB all the time :)!