Oracle 计算两个日期的时间差

select count(*)
from table_a
where
ROUND(TO_NUMBER(END_DATE - START_DATE) * 24) > 6

天：ROUND(TO_NUMBER(END_DATE - START_DATE))
小时：ROUND(TO_NUMBER(END_DATE - START_DATE) * 24)
分钟：ROUND(TO_NUMBER(END_DATE - START_DATE) * 24 * 60)
秒：ROUND(TO_NUMBER(END_DATE - START_DATE) * 24 * 60 * 60)
毫秒：ROUND(TO_NUMBER(END_DATE - START_DATE) * 24 * 60 * 60 * 60)