定义和用法
DATE_SUB() 函数从日期减去指定的时间间隔。
语法
DATE_SUB(date,INTERVAL expr type)
date 参数是合法的日期表达式。expr 参数是您希望添加的时间间隔。
type 参数可以是下列值：
| Type 值 |
|---|
| 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 |
举例：修改订单时间
update order_childs set create_time=date_sub(create_time, interval 1 hour) where child_order_no='订单号' and ss_id in(4,73)
update order_childs set create_time=date_sub(create_time, interval 1 hour)
where child_order_no= 017111545958520441626 and ss_id in(4,73)
#and date(createtime) = curdate()
UPDATE order_childs set create_time=date_sub(create_time, interval 1 day)
where child_order_no= 017120799307620769027 and ss_id in(4,73)
参考网址http://www.w3school.com.cn/sql/func_date_sub.asp
