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

Question

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:S

Answer 1

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;