Extract date (yyyy/mm/dd) from a timestamp in PostgreSQL - sql

Question

I want to extract just the date part from a timestamp in PostgreSQL.
I need it to be a postgresql DATE type so I can insert it into another table that expects a DATE value.
For example, if I have 2011/05/26 09:00:00, I want 2011/05/26
I tried casting, but I only get 2011:
timestamp:date
cast(timestamp as date)
I tried to_char() with to_date():
SELECT to_date(to_char(timestamp, 'YYYY/MM/DD'), 'YYYY/MM/DD')
FROM val3 WHERE id=1;
I tried to make it a function:
CREATE OR REPLACE FUNCTION testing() RETURNS void AS '
DECLARE i_date DATE;
BEGIN
SELECT to_date(to_char(val1, "YYYY/MM/DD"),"YYYY/MM/DD")
INTO i_date FROM exampTable WHERE id=1;
INSERT INTO foo(testd) VALUES (i);
END
What is the best way to extract date (yyyy/mm/dd) from a timestamp in PostgreSQL?

Answer 1

You can cast your timestamp to a date by suffixing it with ::date. Here, in psql, is a timestamp:
# select '2010-01-01 12:00:00'::timestamp;
timestamp
---------------------
2010-01-01 12:00:00
Now we'll cast it to a date:
wconrad=# select '2010-01-01 12:00:00'::timestamp::date;
date
------------
2010-01-01
On the other hand you can use date_trunc function. The difference between them is that the latter returns the same data type like timestamptz keeping your time zone intact (if you need it).
=> select date_trunc('day', now());
date_trunc
------------------------
2015-12-15 00:00:00+02
(1 row)

Answer 2

Use the date function:
select date(timestamp_field) from table
From a character field representation to a date you can use:
select date(substring('2011/05/26 09:00:00' from 1 for 10));
Test code:
create table test_table (timestamp_field timestamp);
insert into test_table (timestamp_field) values(current_timestamp);
select timestamp_field, date(timestamp_field) from test_table;
Test result:

Answer 3

Have you tried to cast it to a date, with <mydatetime>::date ?

Answer 4

In postgres simply :
TO_CHAR(timestamp_column, 'DD/MM/YYYY') as submission_date

Answer 5

This works for me in python 2.7
select some_date::DATE from some_table;

Answer 6

Just do select date(timestamp_column) and you would get the only the date part.
Sometimes doing select timestamp_column::date may return date 00:00:00 where it doesn't remove the 00:00:00 part. But I have seen date(timestamp_column) to work perfectly in all the cases. Hope this helps.

Answer 7

CREATE TABLE sometable (t TIMESTAMP, d DATE);
INSERT INTO sometable SELECT '2011/05/26 09:00:00';
UPDATE sometable SET d = t; -- OK
-- UPDATE sometable SET d = t::date; OK
-- UPDATE sometable SET d = CAST (t AS date); OK
-- UPDATE sometable SET d = date(t); OK
SELECT * FROM sometable ;
t | d
---------------------+------------
2011-05-26 09:00:00 | 2011-05-26
(1 row)
Another test kit:
SELECT pg_catalog.date(t) FROM sometable;
date
------------
2011-05-26
(1 row)
SHOW datestyle ;
DateStyle
-----------
ISO, MDY
(1 row)

Answer 8

You can use date_trunc('day', field).
select date_trunc('day', data_gps) as date_description from some_table;