Below is my query in postgres
select dns_time,update_time from dns_lookup where update_time=current_date;
Here update_time is of type timestamp with time zone.
I have tried this one also.
select dns_time,update_time from dns_lookup where update_time like current_date;
Then also getting no results.
I have records with current_date values.But it is not showing me any records.How to compare timestamp with time zone value with current_date.please help me
Thank you.
First: LIKE on a date or timestamp column does not make any sense.
A timestamp contains a time part so a comparison with a plain date won't work. You need to remove the time from the timestamp by casting it to a date:
where cast(update_time as date) = current_date;
Note that this will void the usage of an index on update_time. If that is a problem you can create a function based index on that expression.
You might be trying to compare a timestamp field with the Date field.
Try casting timestamp to Date
select dns_time,update_time from dns_lookup where update_time::Date=current_date;
Hope this helps.
Related
I have create a datetime with type timestamp. datetime timestamp NOT NULL I am not sure why the output is like this:
I want to extract the day part. I have tried these different approach but in both cases I am getting an error. How can I fix it?
extract(DAY FROM TIMESTAMP min(to_char(u.datetime ,'YYYY-MM-DD HH24:MI'))::timestamp)
EXTRACT(DAY FROM TIMESTAMP min(to_char(u.datetime ,'YYYY-MM-DD HH24:MI')))
date_part('day', min(to_char(u.datetime ,'YYYY-MM-DD HH24:MI')))
As mentioned in response I modified query to be like below and it does work.
extract(day from MIN(datetime)) as Day
All you need is:
select *, extract(day from activated_at) as Day from yourTable;
What you are seeing is a timestamp formatted as text for the display. Underlying data is timestamp as you said, directly use it.
Using psycopg to connect to a Redshift DB I am trying to group by date (in a specific time zone, given at query time). All date_times are stored without time zone (and correspond to UTC timestamps).
I have been trying the following:
SELECT DISTINCT DATE(TIME_ZONE(%(time_zone)s, date_time_dim.timestamp)) AS date,
SUM(meals.sugar_in_g) AS total_sugar
FROM meals
INNER JOIN date_time_dim
ON meals.created_at = date_time_dim.timestamp
WHERE meals.patient_id=%(patient_id)s
AND date_time_dim.timestamp >= %(utc_start_date_time)s
AND date_time_dim.timestamp <= %(utc_end_date_time)s
GROUP BY date
ORDER BY date ASC;
with the following query dictionary:
utc_start_date_time UTC-converted date time
utc_end_date_time UTC-converted date time
patient_id an integer
time_zone, a string, ex: 'US/Hawaii'
The goal being to have one entry for each date (in the given time zone).
What I tried gives me:
function time_zone("unknown", timestamp without time zone) does not exist
What am I missing ?
Edit: This is the same with CONVERT_TIME_ZONE, with and without source time_zone, with and without type casting time_zone to VARCHAR.
The function in Redshift to return a timestamp in a different timezone is TIMEZONE() not TIME_ZONE() - see https://docs.aws.amazon.com/redshift/latest/dg/Date_functions_header.html
The problem is timestamps are like Year-Month-Day Hour:Minute:Second and my WHERE condition needs to ONLY care for the year-month-day portion.
I have tried conditioning for DATE(). I have tried truncate() and have also just simply tried only WHERE created_on = '2019-01-01' and have not have any results show up.
My table columns are:
id|event_status|created_on
created_on being the timestamp field.
[57014] ERROR: canceling statement due to statement timeout
and no results showing up at all.
You need to cast the timestamp to a date:
WHERE created_on::date = date '2019-01-01'`
However that will not be able to use an index on created_on which might be the reason for the timeout.
Another way of writing this that can make use of an index on created_on is to use a range condition:
WHERE created_on >= date '2019-01-01'
and created_on < date '2019-01-02'
You can cast a timestamp into a date. This truncates the time part
WHERE created_on::date = '2019-01-01'::date
I need get only the date from now() at my time zone, I have this query:
SELECT now() AT TIME ZONE 'America/Santiago'
And I'm getting something like this "2015-06-08 23:59:34.142569"
but I need extract only the date, how can I get it?
Thanks.
If you want the server's date,
SELECT current_date;
If you need the date for any timestamp, eg the one you've gotten into your timezone, use date().
SELECT date(now() AT TIME ZONE 'America/Santiago');
Docs: http://www.postgresql.org/docs/current/static/functions-datetime.html
For postgres you want
select current_date;
if you need to extract any of those fields out of the returned value you can use extract
EXTRACT (field FROM source)
I need to convert the value stored in a bigint column to a date field. The first step of the conversion involves converting it to timestamp, and subsequently use the TRUNC method to convert this column to a date value.
However, my query is failing while converting the bigint value to timestamp.
The error that I'm getting is:-
Amazon Invalid operation: cannot cast type bigint to timestamp without time zone;
The query I'm trying for now is something like this:-
select ts::timestamp from events limit 1;
I was able to avoid the time zone error by using the method described in this thread: https://stackoverflow.com/a/36399361
My dates are based on epochs, and I was able to do the following:
SELECT
(TIMESTAMP 'epoch' + contract_start_date * INTERVAL '1 Second ')
FROM
table_name
SELECT TIMESTAMP 'epoch' + {column of bigint}/1000 * INTERVAL '1 second' as adate FROM tbl
If you are starting with a POSIX timestamp, and trying to get a timezone aware datetime value, you will need to supply a timezone - even if you later want to truncate the time part away. I'm not familiar with redshift, but perhaps there is a way to specify you mean UTC.