mysql时间问题

查找格式为：'2011-01-20 10:49:09'
select FROM_UNIXTIME(UNIX_TIMESTAMP('2011-01-20 10:49:09'), '%Y-%m-%d %H:%i:%S') from extracurricular
select * from extracurricular where time ='2011-01-20 10:49:06'

查找格式为：'2011-01-20'
SELECT DATE_FORMAT(time,'%Y-%m-%d') from extracurricular

筛选时间：
select e.time form emp e where e.time <='"+extracurricular.getTempTime()+" 23:59:59' and e.time >='"+extracurricular.getTempTime()+" 00:00:00'"