Question

till today when i was working with MySQL and needed to perform actions with date/time i was using int column with unix timestamp and there was no problems, but today after reading some guides i decided to test timestamp column with “current_timestamp” by default.

So i am interested how to select last month data by column where info is in “2012-09-07 00:23:30” format? And maybe there some tricky queries what will give me data from the start of this month (not last 30 days, but from 09-01 00:00:00 till today) ?

Answer 1

This will give you the last month:

WHERE dateColumn BETWEEN SUBDATE(CURDATE(), INTERVAL 1 MONTH) AND NOW();

This from the start of the month:

WHERE dateColumn BETWEEN STR_TO_DATE('2012-09-01', '%Y-%m-%d') AND NOW();

The BETWEEN is nothing special, it’s just a shortcut for

dateColumn <= ... AND dateColumn >= ....

Hmm, I guess the NOW() comparison is not actually needed, since all the records will be before now.

So just do:

WHERE dateColumn >= STR_TO_DATE('2012-09-01', '%Y-%m-%d')

Dynamic start of current month:

WHERE dateColumn >= CURDATE() - INTERVAL DAY(CURDATE())-1 DAY

All this does is extract the day of the month from the current date, then subtract that many days less one from it.