I have a timestamp with timezone column in one of my tables. I need to extract both hours and minutes from the timestamp with timezone column using extract function but i am unable too.
I tried like this,
extract(hour_minute from immi_referral_user_tb.completed_time) >= '06:30'
but I am getting a syntax error.
I am using extract function in where clause
immi_referral_user_tb.completed_time = timestamp with timezone column
Is there any other way too accomplish this?
You can cast the column to a time data type and compare that to a time value:
immi_referral_user_tb.completed_time::time >= time '06:30'
Related
I am using below condition to truncate date in postgres
to_date(to_char(trunc(appointment_date),'YYYYMMDD')||appointment_end_time,''YYYYMMDDHH24:MI:SS')AS tq
How I can use this in postgres ?
Strange data typing, sometimes requires strange, looking at least, queries. Try (see fiddle)
date_trunc('day',appointment_date)
+ substr(appoinment_end,12)::interval
As your to_char() call uses the format 'HH24:MI:SS' for the "time" column, you can cast that column directly to a time value, e.g. using the :: operator: appointment_end_time::time.
To build a new timestamp from the date part of the appointment_date and the time value, just add them:
appointment_date::date + appointment_end_time::time
So first the timestamp is converted to a date (that does not have a time), and then the time value is added to that, which yields a timestamp.
Note that to_date() returns a date so your code would remove the just added time part again. You would need to use to_timestamp() if you really want a timestamp as the result.
To answer the question's title "how to truncate date in Postgres?" (which in reality refers to a timestamp not a date): you can either cast it to a date (see above) or you can use date_trunc() (not trunc()) with a unit to which it should be truncated. However, date_trunc returns a timestamp not a date value, so you couldn't add a time to the result.
I am new to hive.
I have column in one of my seed tables, say seed_timestamp.
example:
seed.timestamp = '28/04/2020 12:30:54', from this time stamp I want to create a new timestamp such that new_timestamp = '28/04/2020 00:00:00'.
I want to use these timestamps in my where clause of the query such that I check the data from midnight to the seed_timestamp.
In Hive, you can use to_date() to truncate the time part of a timestamp, so just:
to_date(seed_timestamp)
From the documentation:
to_date(string timestamp): returns the date part of a timestamp string
Concatenate date with ' 00:00:00.0':
concat(to_date(seed_timestamp),' 00:00:00.0')
It will produce string compatible with timestamp and you can compare. You can also cast it as timestamp:
cast(concat(to_date(seed_timestamp),' 00:00:00.0') as timestamp)
but it should work without it.
I am extracting three values (server, region, max(date)) from my postgresql> But I want to extract an additional 4th field which should be the numerical addition of 1 to 3rd field. I am unable to use date add function as in the database date field is defined as an integer.
date type in DB
date|integer|not null
tried using cast and date add function
MAX(s.date)::date + cast('1 day' as interval)
Error Received
ERROR: cannot cast type integer to date
Required output
select server, region, max(alarm_date), next date from table .....
testserver, europe, 20190901, 20190902
testserver2, europe, 20191001, 20191002
next date value should be the addition to alarm_date
To convert an integer like 20190901 to a date, use something like
to_date(CAST(s.date AS text), 'YYYYMMDD')
It is a bad idea to store dates as integers like that. Using the date data type will prevent corrupted data from entering the database, and it will make all operations natural.
First solution that came to my mind:
select (20190901::varchar)::date + 1
Which output 2019-09-02 as type date.
Other solutions can be found here.
I am using the following code to convert a column of unix time values into dates in pyspark:
transactions3=transactions2.withColumn('date', transactions2['time'].cast('date'))
The column transactions2['time'] contains the unix time values. However the column date which I create here has no values in it (date = None for all rows). Any idea why this would be?
Use from_unixtime. expr("from_unixtime(timeval)")
I have dates in a postgres database. The problem is they are stored in a string field and have values similar to: "1187222400000" (which would correspond to 07.08.2007).
I would like to convert them into readable dates usind some SQL to_date() expression or something similar but can't come up with the correct syntax to make it work.
There really isn't enough information here for a conclusion, so I propose this 'scientific-wild-ass-guess' to resolve your puzzle. :)
It appears this number is UNIX 'epoch time' in milliseconds. I'll show this example as if your string field had the arbitrary name, 'epoch_milli'. In postgresql you can convert it to a time stamp using this statement:
SELECT TIMESTAMP WITH TIME ZONE 'epoch' + epoch_milli * INTERVAL '1 millisecond';
or using this built-in postgresql function:
SELECT to_timestamp(epoch_milli / 1000)
either of which, for the example '1187222400000', produces the result
"2007-08-15 17:00:00-07"
You can do some of your own sleuthing with quite a few values selected similarly to this:
SELECT to_timestamp(epoch_milli/1000)::DATE
FROM (VALUES (1187222400000),(1194122400000)) AS val(epoch_milli);
"Well, bollocks, man. I just want the date." Point taken.
Simply cast the timestamp to a date to discard the excess bits:
SELECT to_timestamp(epoch_milli / 1000)::DATE
Of course its possible that this value is a conversion or is relative to some other value, hence the request for a second example data point.