Hi I am having a Postgresql query like below to calculate DateTime difference for {1} and {2} in minutes.
CAST(ROUND(EXTRACT(EPOCH from (({2}::timestamp) - ({1}::timestamp)))/60) AS INT)
I want to calculate the difference in hours, minutes and seconds displayed like:
3 hrs 31 minutes 42 secs
What manipulation do I need for displaying like above?
SELECT to_char((col1 - col0), 'HH24 hrs MI "minutes" SS "seconds"') FROM T1;
Here is a sqlfiddle : link
The to_char function takes an interval (an interval is the time span between two timestamps, and subtracting timestamps gives you an interval). It then takes a formatting, and you can apply pretty much what you want.
Formatting functions in PostgreSQL
Try use this sql:
SELECT to_char(column2 - column1, 'DD" days "HH24" hours "MI" minutes "SS" seconds"');
The subtraction of two timestamp or timestamptz values produces an interval. (While subtracting two date values produces an integer!)
Details about date/time types in the manual.
The default text representation of an interval may be sufficient:
SELECT timestamp '2017-1-6 12:34:56' - timestamp '2017-1-1 0:0';
Result is an interval, displayed as:
5 days 12:34:56
If you need the format in the question, precisely, you need to specify how to deal with intervals >= 24 hours. Add 'days'? Or just increase hours accordingly?
#Nobody provided how to use to_char(). But add days one way or the other:
SELECT to_char(ts_col2 - ts_col1, 'DD" days "HH24" hours "MI" minutes "SS" seconds"');
Result:
05 days 12 hours 34 minutes 56 seconds
'days' covers the rest. There are no greater time units in the result by default.
Simple
SELECT
EXTRACT(year FROM LOCALTIMESTAMP(0) - yourFieldTime)||' year '||
EXTRACT(month FROM LOCALTIMESTAMP(0) - yourFieldTime)||' month '||
EXTRACT(day FROM LOCALTIMESTAMP(0) - yourFieldTime)||' day '||
EXTRACT(hour FROM LOCALTIMESTAMP(0) - yourFieldTime)||' hour '||
EXTRACT(minute FROM LOCALTIMESTAMP(0) - yourFieldTime)||' minute '||
EXTRACT(second FROM LOCALTIMESTAMP(0) - yourFieldTime)||' second '
AS full_time_as_you_wish FROM your_table;
Result
full_time_as_you_wish
---------------------------------
0 year 0 month 0 day 0 hour 0 minute 0 second
Related
I have two tables, today's_table and yeterday's_table.
I need to compare the data for an interval of 15 mins at exact same times for today and yesterday.
For example, for below data let's I need to check from 00:00:00 and 00:15:00 on 20201202 and 20201202. So difference should come out as '3' since the yesterday's_table has 8 records and today's_table has 5 records.
today's_table:
Yesterday's table:
I tried something like; (consider now() is 00:15:00)
select count(*) from yeterday's_table where time between now() - interval "24 hours" and now() - interval "23 hours 45 mins"
minus
select count(*) from today's_table where time = now() - interval "15 minutes";
is there any other way to do this?
You can easily do this with subqueries:
SELECT b.c - a.c
FROM (select count(*) as c from yeterdays_table where time between now() - interval '24 hours' and now() - interval '23 hours 45 mins') a,
(select count(*) as c from todays_table where time = now() - interval '15 minutes') b;
Bear in mind you need to single-quote your intervals, and your table names cannot have quotes in them.
Let's say I have a table orders with columns amount and order_date.
I want to be able to group this data by quarters and aggregate the amount, the catch however is that the quarters do not start on January 1st but on any given arbitrary date, say July 12th. These quarters are also split in 13 week intervals. From what I see using something like date_trunc such as:
SELECT SUM(orders.amount), DATE_TRUNC('quarter', orders.order_date) AS interval FROM orders WHERE orders.order_date BETWEEN [date_start] AND [date_end] GROUP BY interval
is out of the question as this forces quarters to start on Jan 1st and it has 'hardcoded' quarter starting dates (Apr 1st, Jul 1st, etc).
I have tried using something like:
SELECT SUM(orders.amount),
to_timestamp(floor((extract('epoch' from orders.order_date / 7862400 )) * 7862400 ) AT TIME ZONE 'UTC' AS interval
FROM orders
WHERE orders.order_date BETWEEN [date_start] AND [date_end]
GROUP BY interval
(where 7862400 is the time interval that I want)
But with this method I cannot figure out how to set the offset for the initial grouping date, in my example I would like it to start from July 12th of each year (then count 13 weeks and start the next quarter, and so on). Hope I was clear and I would appreciate any help!
You can use generate_series() to create the first day of each quarter, join it and group by it.
SELECT quarters.first_day,
quarters.first_day + '13 weeks'::interval last_day,
sum(orders.amount) amount
FROM orders
LEFT JOIN generate_series('2019-07-12'::timestamp,
'2020-07-10'::timestamp,
'13 weeks'::interval) quarters (first_day)
ON quarters.first_day <= orders.order_date
AND quarters.first_day + '13 weeks'::interval > orders.order_date
WHERE orders.order_date BETWEEN [date_start]
AND [date_end]
GROUP BY quarters.first_day,
quarters.first_day + '13 weeks'::interval;
You just need to make sure, that the boundary days you give the generate_series() cover the whole period you want to query, so that depends on your [date_start] and [date_end].
You can generate your own 'quarterly calendar' and use that in place of the Postgers 'quarter' date extraction.
create or replace function quarterly_calendar(annual_date text default extract('YEAR' from current_date)::text)
returns table( quarter integer
, quarter_start_date date
, quarter_end_date date
)
language sql immutable strict leakproof
as $$
with RECURSIVE quarters as
(select 1 qtr, qdt::date q_start_dt, (qdt + interval '90 day' )::date q_end_dt, (qdt+interval '1 year' - interval '1 day')::date last_dt
from ( select date_trunc('year',current_date) + interval '6 month 11 day' qdt) q
union all
select qtr+1, (q_end_dt + interval '1 day')::date, least ((q_end_dt + interval '91 day')::date,last_dt), last_dt
from quarters
where qtr+1 <=5
)
select qtr, q_start_dt, q_end_dt
from quarters;
$$;
-- test
select * from quarterly_calender();
It does actually create 5 quarters. But that is because a year is not a multiple of 13 weeks (or 91 days or 7862400 seconds). In your given year from 12-July-2019 through 11-July-2020 is 2 days (366 days total) over 4 times that interval. You'll have to decide how to handle that 5th quarter. It occurs every year, having either 1 or 2 days. Hope this helps .
I have a CTE-based query in which I retrieve hourly intervals between two given timespans. My query works as following:
Getting start and end datetimes (let's say 07-13-2011 00:21:09 and 07-31-2011 21:11:21)
get the hourly total query values between the hourly intervals (in here it's from 00 to 21, a total of 21 hours but this is parametric and depends on the hours I give for the inputs) for each day. This query works well but there is a problem. It displays hourly amounts but for the start time, it gets all the queries between 00:00:00 and 00:59:59 for each day instead of 00:21:09 - 00:59:59 and same applies for the end time, it gets all the queries between 21:00:00 and 22:00:00 for each day instead of 21:00:00 and 21:11:21. -By the way, the other hour intervals e.g 03:00 - 04:00 etc are currently retrieved normally, no minute and seconds provided, just 1 hour flat intervals- How can I fix that? The query is below, thanks.
WITH cal AS (
SELECT generate_series('2011-02-02 00:00:00'::timestamp , '2012-04-01 05:00:00'::timestamp , '1 hour'::interval) AS stamp
)
, qqq AS (
SELECT date_trunc('hour', calltime) AS stamp
, count(*) AS zcount
FROM mytable
WHERE calltime >= '07-13-2011 00:21:09' AND calltime <='07-31-2011 21:11:21' AND date_part('hour', calltime) >= 0 AND date_part('hour', calltime) <= 21
GROUP BY date_trunc('hour', calltime)
)
SELECT cal.stamp
, COALESCE (qqq.zcount, 0) AS zcount
FROM cal
LEFT JOIN qqq ON cal.stamp = qqq.stamp
WHERE cal.stamp >= '07-13-2011 00:00:00' AND cal.stamp<='07-31-2011 21:11:21' AND date_part('hour', cal.stamp) >= 0 AND date_part('hour', cal.stamp) <= 21
ORDER BY stamp ASC;
EDIT:
What I mean with my problem is, despite giving 00:21:09 for my starting hour on first day, the days after that day calculate the total query count for the first hour interval as count of total queries between 00:00:00-01:00:00 instead of 00:21:09-01:00:00.(by the way this should apply to the first hour interval for every day, I can give 04:30:21 for the starting hour and the day will start to count total queries hourly starting from there etc.- Same applies to the ending hour 21:00:00-21:11:21, only the LAST day in the query results take this interval, other days before it take the query count between hour 21 and 22 by counting all queries between 21:00:00-22:00:00 instead of 21:00:00-21:11:21.
For example, if there are 200 queries between 00:00:00 and 01:00:00 on july 14 2011 (the next day after july 13, the start date) but there are 159 queries between 00:21:09 - 01:00:00, I should get 159 queries instead of 200. Also, if there are 300 queries between 21:00:00-22:00:00 on any random day, and 123 of them are between 21:00:00-21:11:21, I should get 123 queries as result instead of 300. (This applies to every single day, other hourly intervals should be counted as usual such as 01:00-02:00, 20:00-21:00 etc. This is parametric, hourly intervals and start-end times depend on user input-
Adding AND calltime::time >= '00:21:09' AND calltime::time <= '21:11:21' to the WHERE calltime >= '07-13-2011 00:21:09' AND calltime <='07-31-2011 21:11:21' block solved the issue.
I am trying to get the following in Postgres:
select day_in_month(2);
Expected output:
28
Is there any built-in way in Postgres to do that?
SELECT
DATE_PART('days',
DATE_TRUNC('month', NOW())
+ '1 MONTH'::INTERVAL
- '1 DAY'::INTERVAL
)
Substitute NOW() with any other date.
Using the smart "trick" to extract the day part from the last date of the month, as demonstrated by Quassnoi. But it can be a bit simpler / faster:
SELECT extract(days FROM date_trunc('month', now()) + interval '1 month - 1 day');
Rationale
extract is standard SQL, so maybe preferable, but it resolves to the same function internally as date_part(). The manual:
The date_part function is modeled on the traditional Ingres equivalent to the SQL-standard function extract:
But we only need to add a single interval. Postgres allows multiple time units at once. The manual:
interval values can be written using the following verbose syntax:
[#] quantity unit[quantity unit...] [direction]
where quantity is a number (possibly signed); unit is microsecond,
millisecond, second, minute, hour, day, week, month, year, decade,
century, millennium, or abbreviations or plurals of these units;
ISO 8601 or standard SQL format are also accepted. Either way, the manual again:
Internally interval values are stored as months, days, and seconds.
This is done because the number of days in a month varies, and a day
can have 23 or 25 hours if a daylight savings time adjustment is
involved. The months and days fields are integers while the seconds
field can store fractions.
(Output / display depends on the setting of IntervalStyle.)
The above example uses default Postgres format: interval '1 month - 1 day'. These are also valid (while less readable):
interval '1 mon - 1 d' -- unambiguous abbreviations of time units are allowed
IS0 8601 format:
interval '0-1 -1 0:0'
Standard SQL format:
interval 'P1M-1D';
All the same.
Note that expected output for day_in_month(2) can be 29 because of leap years. You might want to pass a date instead of an int.
Also, beware of daylight saving : remove the timezone or else some monthes calculations could be wrong (next example in CET / CEST) :
SELECT DATE_TRUNC('month', '2016-03-12'::timestamptz) + '1 MONTH'::INTERVAL
- DATE_TRUNC('month', '2016-03-12'::timestamptz) ;
------------------
30 days 23:00:00
SELECT DATE_TRUNC('month', '2016-03-12'::timestamp) + '1 MONTH'::INTERVAL
- DATE_TRUNC('month', '2016-03-12'::timestamp) ;
----------
31 days
This works as well.
WITH date_ AS (SELECT your_date AS d)
SELECT d + INTERVAL '1 month' - d FROM date_;
Or just:
SELECT your_date + INTERVAL '1 month' - your_date;
These two return interval, not integer.
SELECT cnt_dayofmonth(2016, 2); -- 29
create or replace function cnt_dayofmonth(_year int, _month int)
returns int2 as
$BODY$
-- ZU 2017.09.15, returns the count of days in mounth, inputs are year and month
declare
datetime_start date := ('01.01.'||_year::char(4))::date;
datetime_month date := ('01.'||_month||'.'||_year)::date;
cnt int2;
begin
select extract(day from (select (datetime_month + INTERVAL '1 month -1 day'))) into cnt;
return cnt;
end;
$BODY$
language plpgsql;
You can write a function:
CREATE OR REPLACE FUNCTION get_total_days_in_month(timestamp)
RETURNS decimal
IMMUTABLE
AS $$
select cast(datediff(day, date_trunc('mon', $1), last_day($1) + 1) as decimal)
$$ LANGUAGE sql;
How do I add a dynamic (column based) number of days to NOW?
SELECT NOW() + INTERVAL a.number_of_days "DAYS" AS "The Future Date"
FROM a;
Where a.number_of_days is an integer?
I usually multiply the number by interval '1 day' or similar, e.g.:
select now() + interval '1 day' * a.number_of_days from a;
I know this is a year old, but if you need to use a column to specify the actual interval (e.g. 'days', 'months', then it is worth knowing that you can also CAST your string to an Interval, giving:
SELECT now()+ CAST(the_duration||' '||the_interval AS Interval)
So the the original question would become:
SELECT now() + CAST(a.number_of_days||" DAYS" AS Interval) as "The Future Date" FROM a;
I prefer this way. I think its pretty easy and clean.
In Postgres you need interval to use + operator with timestamp
select (3||' seconds')::interval;
select now()+ (10||' seconds')::interval,now();
where you can use seconds, minutes, days, months...
and you can replace the numbers to your column.
select now()+ (column_name||' seconds')::interval,now()
from your_table;
Use make_interval()
SELECT NOW() + make_interval(days => a.number_of_days) AS "The Future Date"
FROM a;
But in general it might be a better idea to use a column defined as interval, then you can use any unit you want when you store a value in there.
To creating intervals those based on column values, I recommend to add two columns in your table. For example, column "period_value"::INT4 and column "period_name"::VARCHAR.
Column "period_name" can store the following values:
microsecond
milliseconds
second
minute
hour
day
week
month
quarter
year
decade
century
millennium
+--------------+-------------+
| period_value | period_name |
+--------------+-------------+
| 2 | minute |
+--------------+-------------+
Now you can write:
SELECT NOW() - (period_value::TEXT || ' ' || period_name::TEXT)::INTERVAL FROM table;
If we have field with interval string value such as '41 years 11 mons 4 days' and want to convert it to date of birth use this query :
UPDATE "february14" set dob = date '2014/02/01' - (patient_age::INTERVAL)
dob is date field to convert '41 years 11 mons 4 days' to '1972/10/14' for example
patient_age is varchar field that have string like '41 years 11 mons 4 days'
And this is query to convert age back to date of birth
SELECT now() - INTERVAL '41 years 10 mons 10 days';
Updating based on a column ID was a useful way to create some randomised test data for me.
update study_histories set last_seen_at = now() - interval '3 minutes' * id;