How to subtract 30 days from the current datetime in mysql?

To anyone who doesn't want to use DATE_SUB, use CURRENT_DATE:

SELECT CURRENT_DATE - INTERVAL 30 DAY

SELECT * FROM table
WHERE exec_datetime BETWEEN DATE_SUB(NOW(), INTERVAL 30 DAY) AND NOW();

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