mysql已知生日查年龄 mysql用出生日期计算年龄

mysql 年龄计算（根据生日字段）

year( from_days( datediff( now( ), birthdate))) //获取年龄
 
now() 当前时间,精确到秒
datediff(begindate,enddate):返回两日期之间相关的日数.
from_days(days):从0000-00-00开始,根据传入的日数,返回一个日期;
year(date):获取日期上的年


[条件查找年龄在18到30]

$map .= " AND year(from_days(datediff(now( ),MbBirthDay))) >=18  AND year(from_days(datediff(now( ),MbBirthDay))) <30 ";

YEAR(CURDATE())-YEAR(birthday)-(RIGHT(CURDATE(),5)<RIGHT(birthday,5)

SELECT NOW(),CURDATE(),CURTIME()

NOW() // 2012-10-12 16:25:43     CURDATE() //2012-10-12    CURTIME//16:12:45

right(CURDATE(),5)截取右边5个字段