获得日期时间
select now() #执行开始时获得
select sysdate() #函数执行时获得
select now(), sleep(3), sysdate() ###
转换字符为时间
str_to_date('2019-01-11 11:11:11', '%Y-%m-%d %H:%i:%s')
//SELECT str_to_date('2019-01-11 15:11:11', '%Y-%m-%d %H:%i:%s')
日期添加/减少指定的时间间隔(date 参数是合法的日期 expr参数时间间隔)
DATE_ADD(date, INTERVAL expr type)
DATE_SUB(date, INTERVAL expr type)
type:
MICROSECOND | SECOND | MINUTE | HOUR | DAY | WEEK | MONTH |
QUARTER | YEAR | SECOND_MICROSECOND | MINUTE_MICROSECOND |
MINUTE_SECOND | HOUR_MICROSECOND | HOUR_SECOND | HOUR_MINUTE |
DAY_MICROSECOND | DAY_SECOND | DAY_MINUTE | DAY_HOUR | YEAR_MONTH
示例:
DATE_ADD(now(), INTERVAL 8 HOUR) //加八小时
DATE_ADD(create_date, INTERVAL 8 HOUR) //加八小时
DATE_ADD(now(), INTERVAL 1 DAY) //加一天
//SELECT DATE_ADD(now(), INTERVAL 1 DAY)
日期转换函数、时间转换函数date_format(date,format), time_format(time,format)
date_format(now(), '%Y-%m-%d %H:%i:%s')
time_format(now(), '%H:%i')
//select date_format(now(), '%Y-%m-%d %H:%i:%s')
sql更新时间增加八小时
UPDATE user
SET create_date = DATE_ADD(create_date, INTERVAL 8 HOUR),
update_date = DATE_ADD(update_date, INTERVAL 8 HOUR)
WHERE create_date < STR_TO_DATE('2019-01-11 11:11:11', '%Y-%m-%d %h:%i:%s');