MySQL has many date and time functions to manipulate and compare dates and time, the
reference documentation form 5.1 version. If you want to add a day to a datetime or date field:
SELECT now(), now() + INTERVAL 10 DAY;
If you run the query above you will see the current date and the current date plus ten days. You can add or subtract even hours, second and more.
SELECT *
FROM article
WHERE approved=1
AND (
(birth <> now( ))
OR (news=1 OR never_expires=1)
)
The example above shows a query which loads the articles between the bith and now and between now and the expiry (death) date. If hte article is a news or should not expire, the date comparison is not taken into consideration.
If you want the current time:
SELECT CURTIME();
If you want to get the day of a date:
SELECT DAY('2009-12-15');
If you want the difference, in days, between two dates:
SELECT DATEDIFF('2007-12-30 23:59:59','2007-12-20');
The result is 10 because MyQSL subtract the second value from the first. The documentation is quite clear and complete.
Labels: MySql