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

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(开发者_C百科) 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?

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)

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:

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

In postgres simply :

TO_CHAR(timestamp_column, 'DD/MM/YYYY') as submission_date

This works for me in python 2.7

 select some_date::DATE from some_table;

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.

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)

You can use date_trunc('day', field).

select date_trunc('day', data_gps) as date_description from some_table;