select * from `user` where to_days(birthday) = to_days(CURDATE());
select * from `user` where to_days(CURDATE()) - to_days(birthday)<=1;
select * from `user` where birthday > DATE_SUB(CURDATE(),INTERVAL 7 DAY);
select * from `user` where birthday > DATE_SUB(CURDATE(), INTERVAL 3 MONTH)
select * from `user` where birthday > DATE_SUB(CURDATE(), INTERVAL 1 YEAR);
select * from `user` where quarter(birthday) = quarter(CURDATE());
select * from `user` where quarter(birthday) = quarter(DATE_SUB(CURDATE(), INTERVAL 1 QUARTER));
select * from `user` where year(CURDATE()) - year(birthday) = 28 ;
select * from `user` where month(birthday) = 8 ;
select * from `user` where date_format(birthday,'%Y-%m-%d')='2017-07-07';
select * from `user` where birthday between '1888-5-1 00:00:00' and '2017-9-3 00:00:00';
select * from `user` where birthday > '1989-5-1' and birthday < '2017-5-1';