Oracle计算两个时间戳相差秒数，精确到毫秒

with t as

(select to_timestamp('2015-01-01 11:13:15.023456',

'yyyy-mm-dd hh24:mi:ss.ff9') t1,

to_timestamp('2015-01-01 12:13:15.123556',

'yyyy-mm-dd hh24:mi:ss.ff9') t2

from dual)

select
abs((trunc(t1 -
0,
'mi')
-
trunc((t2 -
0),
'mi'))
*
24
*
60
*
60
+

extract(second
from t1 - t2))

from t

输出结果： 3600.1001