DATE_FORMAT

select city_name,begin_time from t_city_parttime_info where enable=1 and DATE_FORMAT(begin_time,"%H")="00" ;

http://www.w3schools.com/sql/func_date_format.asp

FROM_UNIXTIME 與 UNIX_TIMESTAMP

SELECT FROM_UNIXTIME( 1249488000, '%Y-%m-%d' ) 
UNIX_TIMESTAMP() 是與之相對(duì)正好相反的時(shí)間函數(shù)
SELECT UNIX_TIMESTAMP() ;
SELECT UNIX_TIMESTAMP('2009-08-06') ;

http://www.cnblogs.com/showker/archive/2010/03/18/1689054.html