1.unix时间戳---》 时间

秒

# SELECT TIMESTAMP WITH TIME ZONE 'epoch' + 1471313356 * INTERVAL '1 second';

        ?column?        

------------------------

 2016-08-16 10:09:16+08

(1 row)

# SELECT TIMESTAMP WITHOUT TIME ZONE 'epoch' + 1471313356 * INTERVAL '1 second';

      ?column?       

---------------------

 2016-08-16 02:09:16

(1 row)

# SELECT TIMESTAMP WITH TIME ZONE 'epoch' + 1461033436.269 * INTERVAL '1 second';

          ?column?          

----------------------------

 2016-04-19 10:37:16.269+08

(1 row)

毫秒

# SELECT TIMESTAMP WITH TIME ZONE 'epoch' + 1464186650352 * INTERVAL '1 milliseconds';

          ?column?          

----------------------------

 2016-05-25 22:30:50.352+08

(1 row)

# SELECT TIMESTAMP WITHOUT TIME ZONE 'epoch' + 1464186650352 * INTERVAL '1 milliseconds';

        ?column?         

-------------------------

 2016-05-25 14:30:50.352

(1 row)

# 

2.时间----》 Unix时间戳

秒

# SELECT EXTRACT(EPOCH FROM TIMESTAMP WITHOUT TIME ZONE '2016-05-25 14:30:50.352');

   date_part    

----------------

 1464186650.352

(1 row)

# SELECT EXTRACT(EPOCH FROM TIMESTAMP WITH TIME ZONE '2016-05-25 14:30:50.352');

   date_part    

----------------

 1464157850.352

(1 row)

毫秒

# SELECT EXTRACT(EPOCH FROM TIMESTAMP WITHOUT TIME ZONE '2016-05-25 14:30:50.352')*1000;

   ?column?    

---------------

 1464186650352

(1 row)

# 

postgres=# SELECT extract(epoch FROM '2017-02-07 11:18:23.098+08'::timestamp with time zone);

   date_part    

----------------

 1486437503.098

(1 row)

postgres=# select to_timestamp(1486437503.098);

        to_timestamp        

----------------------------

 2017-02-07 11:18:23.098+08

(1 row)

postgres=#