毫秒与时间互相转换

--timestamp转为字符型

select to_char(systimestamp,'yyyy-mm-dd hh24:mi:ss.ff6') from dual;

SELECT CAST(sysdate as timestamp) from dual;

--unix时间戳与date时间互转
SELECT oracle_to_unix(SYSDATE),unix_to_oracle(1551774286),oracle_to_unix(SYSDATE) FROM dual;

--当前毫秒级时间,毫秒长度最大为6，但是只有3位有效。所以计算时都使用3位进行计算

select to_char(current_timestamp,'yyyy-mm-dd hh24:mi:ss.ff6') from dual;

--字符串转为 timestamp类型

select to_timestamp('2012-02-03 10:29:46.453234','yyyy-mm-dd hh24:mi:ss.ff6') from dual;

--timestamp转为字符型

select to_char(systimestamp,'yyyy-mm-dd hh24:mi:ss.ff6') from dual;

--当前毫秒级时间

select to_char(current_timestamp,'yyyy-mm-dd hh24:mi:ss.ff6') from dual;
select current_timestamp from dual;

SELECT (SYSDATE - TO_DATE('1970-01-01 00:00:00', 'YYYY-MM-DD HH24:MI:SS')) *
       86400000 + TO_NUMBER(TO_CHAR(SYSTIMESTAMP(6), 'FF')) AS MILLIONS,
       SYSDATE,
        TO_NUMBER(TO_CHAR(SYSTIMESTAMP(6), 'FF')),
        (SYSDATE - TO_DATE('1970-01-01 00:00:00', 'YYYY-MM-DD HH24:MI:SS')) *
       86400000
  FROM DUAL;

--当前时间转毫秒数(2019/3/5 15:53:41)->(1551801221228)
SELECT (SYSDATE - TO_DATE('1970-01-01 00:00:00', 'YYYY-MM-DD HH24:MI:SS')) *
       86400000 + TO_NUMBER(TO_CHAR(SYSTIMESTAMP(3), 'FF')) AS MILLIONS,
       SYSDATE
  FROM DUAL;

--毫秒数转时间(1551801221228)->(2019-03-05 15:52:55.576)
SELECT MILLISECONDS2TIMESTAMP(1551774330) FROM DUAL;

SELECT TO_CHAR(MILLISECONDS2TIMESTAMP(1551804255181),
               'yyyy-mm-dd hh24:mi:ss.ff3')
  FROM DUAL;

--毫秒数转时间(1551801221228)->(2019/3/5 15:52:56)  
select num_to_date(1551804255181) from dual;

SELECT TO_CHAR(1551804255181 / (1000 * 60 * 60 * 24) +  
       TO_DATE('1970-01-01 00:00:00', 'YYYY-MM-DD HH24:MI:SS'), 'YYYY-MM-DD HH24:MI:SS') AS CDATE,
       to_timestamp(TO_CHAR(1551804255181 / (1000 * 60 * 60 * 24) +  
       TO_DATE('1970-01-01 00:00:00', 'YYYY-MM-DD HH24:MI:SS'), 'YYYY-MM-DD HH24:MI:SS'),'yyyy-mm-dd hh24:mi:ss.ff3') AS to_timestamp,
       to_char(to_timestamp(TO_CHAR(1551804255181 / (1000 * 60 * 60 * 24) +  
       TO_DATE('1970-01-01 00:00:00', 'YYYY-MM-DD HH24:MI:SS'), 'YYYY-MM-DD HH24:MI:SS'),'yyyy-mm-dd hh24:mi:ss.ff3'),'yyyy-mm-dd hh24:mi:ss.ff3') AS to_char1,
       TO_CHAR(MILLISECONDS2TIMESTAMP(1551804255181),
               'yyyy-mm-dd hh24:mi:ss.ff3') AS to_char
FROM dual t;

 

函数下载地址：

毫秒与时间互相转换-精确到秒

https://download.csdn.net/download/qinshihuanglove2/10997979

毫秒与时间互相转换-精确到毫秒

https://download.csdn.net/download/qinshihuanglove2/10997973

 

oracle中日期类型与unix 时间戳的转换

https://download.csdn.net/download/qinshihuanglove2/10998008