How to write bigint (timestamp in milliseconds) value as timestamp in postgresql

问题

I'm trying to store in timestamp with timezone field my value. It is in milliseconds from 1970.

select TO_CHAR(TO_TIMESTAMP(1401432881230), 'DD/MM/YYYY HH24:MI:SS.MS')

Expected 30/5/2014 11:29:42 10:54:41.230, but get 22/08/46379 23:27:02.000

回答1:

Unix timestamps measures time with seconds, and not milliseconds (almost everywhere, in PostgreSQL too).

Therefore you need to call

SELECT TO_TIMESTAMP(1401432881230 / 1000);

If you want to preserve milliseconds, call with double precision:

SELECT TO_TIMESTAMP(1401432881230::double precision / 1000);

回答2:

This is how I convert ms to timestamp and keep ms instead seconds.The accepted answer will drop ms.

WITH ts AS (SELECT 1401432881230 AS ts)
SELECT to_timestamp(ts / 1000) + ((ts % 1000 ) || ' milliseconds') :: INTERVAL
FROM ts;

-- FOR ALTER COLUMN
ALTER TABLE  my_info
  ALTER COLUMN tstmp TYPE TIMESTAMP USING to_timestamp(tstmp / 1000) + ((tstmp % 1000) || ' milliseconds') :: INTERVAL;

回答3:

Okay, I understood. My INSERT should looks like:

INSERT INTO events (timestamp) VALUES (to_timestamp(TO_CHAR(TO_TIMESTAMP(1401432881222 / 1000), 'YYYY-MM-DD HH24:MI:SS') || '.' || (1401432881222%1000), 'YYYY-MM-DD HH24:MI:SS.MS'))

I'm converting bigint-timestamp with milliseconds to text with required format ('YYYY-MM-DD HH24:MI:SS.MS') and pass it to to_timestamp function.

来源：https://stackoverflow.com/questions/23950025/how-to-write-bigint-timestamp-in-milliseconds-value-as-timestamp-in-postgresql