Oracle计算时间差

时间差=终止时间-开始时间

1.字符串型（要转化成数字类型）

天：ROUND(TO_NUMBER(TO_DATE(A.EST_DATE,'YYYYMMDDHH24MISS')-TO_DATE(A.INS_DATE,'YYYYMMDDHH24MISS')))

小时：ROUND(TO_NUMBER(TO_DATE(A.EST_DATE,'YYYYMMDDHH24MISS')-TO_DATE(A.INS_DATE,'YYYYMMDDHH24MISS'))*24)

分钟：ROUND(TO_NUMBER(TO_DATE(A.EST_DATE,'YYYYMMDDHH24MISS')-TO_DATE(A.INS_DATE,'YYYYMMDDHH24MISS'))*24*60)

秒：ROUND(TO_NUMBER(TO_DATE(A.EST_DATE,'YYYYMMDDHH24MISS')-TO_DATE(A.INS_DATE,'YYYYMMDDHH24MISS'))*24*60*60)

毫秒：ROUND(TO_NUMBER(TO_DATE(A.EST_DATE,'YYYYMMDDHH24MISS')-TO_DATE(A.INS_DATE,'YYYYMMDDHH24MISS'))*24*60*60*60)

2.数字型

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)