Oracle中时间戳之间的差异(以毫秒为单位)
问题描述：
我有表test1并具有带有时间戳记数据类型的一列DOJ，其记录很少，如下所示. 在这里，我需要doj和systimestamp之间的毫秒数差异.
I have table test1 and have one column DOJ with timestamp datatype having few records as shown below. Here i need the difference im milliseconds between doj and systimestamp.
SELECT DOJ FROM TEST1;
DOJ
----------------------------
21-MAR-14 09.25.34.514526000
21-MAR-14 09.25.34.520345000
22-MAR-14 09.25.34.523144000
22-MAR-14 09.25.34.527770000
23-MAR-14 09.25.34.532482000
23-MAR-14 09.25.34.535603000
24-MAR-14 09.25.34.538556000
24-MAR-14 09.25.34.541729000
SELECT SYSTIMESTAMP FROM DUAL;
SYSTIMESTAMP
--------------
24-MAR-14 09.48.10.251556000 +00:00
有人可以帮我吗?
答
select
extract(second from systimestamp - doj) * 1000
from
test1;