insert.sql

\set file_path '/home/user/sql/'
\set sq '\''
\set file :sq:file_path:file_name:sq

\set command '\\copy tmp from ' :file ' delimiter ':sq',':sq ' csv header;'

create temp table tmp (
  aaa integer
, bbb varchar
, ccc varchar
);

:command

INSERT INTO test_table (
  aaa
, bbb
, ccc
, create_datetime
, update_datetime
)
SELECT
  tmp.aaa
, tmp.bbb
, tmp.ccc
, current_timestamp
, current_timestamp
FROM tmp;