Re: Timestamp with timezone query

From: "Harry Hehl" <Harry(dot)Hehl(at)diskstream(dot)com>
To: <pgsql-general(at)postgresql(dot)org>
Subject: Re: Timestamp with timezone query
Date: 2006-09-26 17:21:01
Message-ID: 6AD4F3A63B017C4FB074E2C895AD185488CB73@EXCHSRV.waterloonetworking.net
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-general

Not having any luck with this.
TIME WITH TIME ZONE columns are being handle slightly different for
TIMESTAMP WITH TIME ZONE.

If I have the following data...

mydate | mytime
------------------------------------------------------------------------
--------
2006-09-26 12:12:08-04 | 12:12:08-04

I tried a different method to query timestamps with a timezone. The
following returns a row.
select mytime from table where mydate = timestamp with time zone
'2006-09-26 16:12:08+00'

If I do the samething with the time column, I do not get anything back.
select mytime from table where mytime = mytime with time zone
'16:12:08+00';

The purpose of the 'mytime' column was to do searchs on only the time
portion of a timestamp.

Is it maybe possible to search on a timestamp but wildcare the date
part?
As I mentioned, I am getting timestamp and time from a client that is
converted to utc.

Therefore is it possible to build a query like :

Select * from table where mydate = timestamp with time zone '%
16:12:08+00' i.e. wildcard the date portion?



________________________________

From: Brandon Aiken [mailto:BAiken(at)winemantech(dot)com]
Sent: Tuesday, September 26, 2006 12:47 AM
To: Harry Hehl; pgsql-general(at)postgresql(dot)org
Subject: RE: [GENERAL] Timestamp with timezone query

I'm not at my dev station to check, but what about:
SELECT myTime AT TIME ZONE 'UTC' FROM theTable;

Then try:
SELECT myTime AT TIME ZONE 'UTC' FROM theTable WHERE myTime =
'19:30:00-00';

Or:
SELECT myTime AT TIME ZONE 'UTC' FROM theTable WHERE myTime = TIME WITH
TIME ZONE '19:30:00-00';

If that doesn't work you might try extracting epoch to convert the time
to an integer:
SELECT myDate, myTime FROM theTable where EXTRACT(EPOCH FROM myTime) =
EXTRACT(EPOCH FROM TIME WITH TIME ZONE '19:30:00-00');

Brandon Aiken

-----Original Message-----
From: Harry Hehl [mailto:Harry(dot)Hehl(at)diskstream(dot)com]
Sent: Mon 9/25/2006 9:21 PM
To: Brandon Aiken
Subject: RE: [GENERAL] Timestamp with timezone query

Hi Brandon,

>>postgres=# select time with time zone '00:30:00-05' at time zone
'utc';
This is not quite when I am doing. The time I get is already in UTC.

This is what I have...

date | timestamp(6) with time zone |
time | time(6) with time zone |

select date,time from test where date = '2000-02-10 19:30:00' at time
zone 'utc';
date | time
------------------------+-------------
2000-02-11 00:30:00-05 | 00:30:00-05

I get date and time from a remote client in UTC. In the above case
(which works) '2000-02-10 19:30:00' is UTC, so the query returns the
desired result. I have to do the same thing with time.

So I tried...

select date,time from test where time = '19:30:00' at time zone 'utc';
ERROR: invalid input syntax for type timestamp with time zone:
"19:30:00"

select date,time from test where time = time with time zone '19:30:00'
at time zone 'utc';
select date,time from test where time = time with time zone
'19:30:00-00' at time zone 'utc';

Both return...
date | time
------+------
(0 rows)

This get close (I think)
select cast( ('2000-01-01 19:30:00' at time zone 'utc') as time );
timezone
----------
00:30:00

but when used in a table query...

select date,time from test where time = cast( ('2000-01-01 19:30:00' at
time zone 'utc') as time );
date | time
------+------
(0 rows)

Any ideas would be much appreciated.

Thanks
Harry

-----Original Message-----
From: Brandon Aiken [mailto:BAiken(at)winemantech(dot)com]
Sent: Mon 9/25/2006 5:42 PM
To: Harry Hehl
Subject: RE: [GENERAL] Timestamp with timezone query

Hm? Works for me:

postgres=# select time with time zone '00:30:00-05' at time zone 'utc';
timezone
-------------
05:30:00+00
(1 row)

What are you trying to do with the query?

--
Brandon Aiken
CS/IT Systems Engineer

-----Original Message-----
From: pgsql-general-owner(at)postgresql(dot)org
[mailto:pgsql-general-owner(at)postgresql(dot)org] On Behalf Of Harry Hehl
Sent: Monday, September 25, 2006 5:34 PM
To: pgsql-general(at)postgresql(dot)org
Subject: Re: [GENERAL] Timestamp with timezone query

Thanks, that does it.
select * from table where column = '2006-02-10 19:30:00' AT TIME ZONE
'utc';

I also have a TIME WITH TIMEZONE column that I have to do the same thing
with but AT TIME ZONE can't be used directly. I tried several approaches
but I either get incorrect results or syntax errors. Is there a way to
do the same thing with TIME columns?

-----Original Message-----
From: Brandon Aiken [mailto:BAiken(at)winemantech(dot)com]
Sent: Monday, September 25, 2006 11:39 AM
To: Harry Hehl; pgsql-general(at)postgresql(dot)org
Subject: RE: [GENERAL] Timestamp with timezone query

Use the AT TIME ZONE construct:

http://www.postgresql.org/docs/8.1/interactive/functions-datetime.html#F
UNCTIONS-DATETIME-ZONECONVERT

--
Brandon Aiken
CS/IT Systems Engineer

-----Original Message-----
From: pgsql-general-owner(at)postgresql(dot)org
[mailto:pgsql-general-owner(at)postgresql(dot)org] On Behalf Of Harry Hehl
Sent: Monday, September 25, 2006 11:06 AM
To: pgsql-general(at)postgresql(dot)org
Subject: [GENERAL] Timestamp with timezone query

Hello,

I have a table with TIMESTAMP WITH TIMEZONE column. I would like to
query for a timestamp using a different timezone.

For example if a column contains '2006-02-11 00:30:00-05'
select * from table where column='2006-02-10 19:30:00+00' would return
the column containing '2006-02-11 00:30:00-05'.

From section 8.5.1.3 "To ensure that a literal is treated as timestamp
with time zone, give it the correct explicit type: TIMESTAMP WITH TIME
ZONE '2004-10-19 10:23:54+02'"

So I tried:

select * from table where column = TIMESTAMP WITH TIME ZONE '2006-02-10
19:30:00+00'

But it did not returned the desired result.

I am getting the timestamp as UTC and want to use to build a query, but
I don't want Postgres convert the timestamp. Is there anyway to do this?

Thanks

---------------------------(end of broadcast)---------------------------
TIP 6: explain analyze is your friend

---------------------------(end of broadcast)---------------------------
TIP 2: Don't 'kill -9' the postmaster

Browse pgsql-general by date

  From Date Subject
Next Message MaXX 2006-09-26 18:35:03 Re: Restart after poweroutage
Previous Message Phillip Tornroth 2006-09-26 17:10:23 Solution for rolling back many transactions?