oracle函数 extract(c1 from d1)

【功能】：日期/时间d1中，参数(c1)的值

【参数】：d1日期型(date)/日期时间型(timestamp),c1为字符型(参数)

【参数表】：c1对应的参数表详见示例

【返回】：字符

【示例】

select

extract(hour from timestamp '2001-2-16 2:38:40 ' ) 小时,

extract(minute from timestamp '2001-2-16 2:38:40 ' ) 分钟,

extract(second from timestamp '2001-2-16 2:38:40 ' ) 秒,

extract(DAY from timestamp '2001-2-16 2:38:40 ' ) 日,

extract(MONTH from timestamp '2001-2-16 2:38:40 ' ) 月,

extract(YEAR from timestamp '2001-2-16 2:38:40 ' ) 年

from dual;

select extract (YEAR from date '2001-2-16' ) from dual;

select sysdate 当前日期,

extract(hour from timestamp timestamp sysdate) 小时,

extract(DAY from sysdate ) 日,

extract(MONTH from sysdate ) 月,

extract(YEAR from sysdate ) 年

from dual;