Thread: select extract and subqueries

Try SELECT EXTRACT(EPOCH FROM columnname) FROM tablename;

This will give you the number of seconds from 1970-01-01 00:00:00 to the
date/time in your column.

-----Original Message-----
From: mike sears [mailto:matrix@quadrent.net]
Sent: 21 November 2001 02:13
To: pgsql-general@postgresql.org
Subject: [GENERAL] select extract and subqueries


I don't know if its possiable or not but I've been having problems trying to
extract the timestamp out of one of my columns so that I can compare the
dates.

if I do the following it gives me a proper epoch
en=# SELECT EXTRACT(EPOCH FROM TIMESTAMP '2001-11-20');
 date_part
------------
 1006232400
(1 row)

but if I try to use a subquery to get the date it gives me a parse error.

en=# SELECT EXTRACT (EPOCH FROM TIMESTAMP (select date from master));
ERROR:  parser: parse error at or near "select"

is this simply just a limitation of the extract funtion or am I missing
something?

Mike