Question

I have table (named tasks) with column created_at that, basically, contains UNIX time-stamp.

I need to select only those results that are created in specified time-interval.

Intervals are today, tomorrow, this week and this month.

I think that if I convert time-stamp to YYYY-MM-DD HH:MM:SS format, MySQL can handle it.

Also, I think that I need to use BETWEEN there as well.

So, I pass time-stamp to query and compare (check?) that it’s in the specified interval with time-stamp that is stored in the database. To convert, I need to use FROM_UNIXTIME, right?

How to specify those intervals? Thanks in an advice!

Answer 1

You need to convert UNIX_TIMESTAMP.

Query

SELECT * FROM tasks
WHERE created_at BETWEEN UNIX_TIMESTAMP(DATE_SUB(now(),INTERVAL 1 DAY)) 
                     AND UNIX_TIMESTAMP(now())

You can alter the interval for week, month etc by doing:

INTERVAL 1 WEEK
INTERVAL 1 MONTH
INTERVAL 1 YEAR

MySQL will automatically take the length of months and leap years etc into account.

In the above query MySQL will be able to use an index, speeding things up a lot.
Make sure not to use a function on your column, because in that case MySQL cannot use an index on that field, causing major slowness.

Coding horror, very slow

SELECT * FROM tasks 
WHERE FROM_UNIXTIME(created_at) BETWEEN DATE_SUB(now(),INTERVAL 1 DAY) 
                                    AND now()

See: http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html#function_date-add