Getting a count of timestamps that fall into each 5 minute bucket - sql

I have a table of timestamps. I'd like to group them into 5 minute buckets and get the count of timestamps in that bucket. I having some trouble getting the SQL quite right. I am using Postgres. It's telling me the timestamp column in the last line doesn't exist, but it's defined as an alias.
SELECT
TIMESTAMP WITH TIME ZONE 'epoch' +
INTERVAL '1 second' * round(extract('epoch' from my_timestamp) / 300) * 300
as timestamp,
count(my_timestamp)
FROM logs
GROUP BY
round(extract('epoch' from timestamp) / 300)

I think your GROUP BY is off. Try this:
SELECT TIMESTAMP WITH TIME ZONE 'epoch' + INTERVAL '1 second' * round(extract('epoch' from my_timestamp) / 300) * 300 as timestamp,
count(*)
FROM (values (now())) logs(my_timestamp)
GROUP BY timestamp

Related

get time series in 10 minutes of interval

I am generating one time-series from using below query.
SELECT date_trunc('min', dd):: TIMESTAMP WITHOUT TIME zone as time_ent
FROM generate_series ( timestamp '2021-12-09 06:34:37' + ((DATE_PART('min', timestamp '2021-12-09 06:34:37')::integer % 2) || ' minutes') :: INTERVAL
, '2021-12-10 06:34:37'::timestamp
, '20 min'::interval) dd
and it will give me output like below.
2021-12-09 06:34:00.000
2021-12-09 06:54:00.000
2021-12-09 07:14:00.000
2021-12-09 07:34:00.000
but I need output like.
2021-12-09 06:40:00.000
2021-12-09 07:00:00.000
2021-12-09 07:20:00.000
2021-12-09 07:40:00.000
currently, the time series hours depend upon the timestamp that I pass. in above it gives me mins like 34,54,14...but I want the mins like 40,00,20...it should not depend on the time I passed in query. I tried with timestamp '2021-12-09 06:34:37' + ((DATE_PART('min', timestamp '2021-12-09 06:34:37')::integer % 2) || ' minutes') :: INTERVAL but not any success.
Based on your description, I assumed that you want to create a series of timestamps for 00, 20, 40 minute at each hour until the next day.
select *
from (
select date_trunc('hour', current_timestamp) + i * interval '20 minutes' as ts
from generate_series(1, 24*3) as t(i)) t
where ts between current_timestamp and current_timestamp + interval '1 day'
The key idea here is to truncate the current_timestamp to 00 minute first. This becomes the start of the series. Then filter out the generated timestamps outside the range you want. You may need to adjust the second argument of generate_series function, depending on your requirement.
Or you can just generate a series of timestamp like the following:
select *
from (
select ts
from generate_series(
date_trunc('hour', current_timestamp),
current_timestamp + interval '1 day',
interval '20 minutes') as t(ts)) as t
where ts between current_timestamp and current_timestamp + interval '1 day'
Here, you still need to trunc your timestamp to hour first so the start of the series at 00 minute.

Trying to get HH:MM:SS from milliseconds in Presto

I'm trying to convert milliseconds to format HH:MM:SS or MM:SS, but I keep getting the same error.
Here's the error:
java.sql.SQLException: [Simba][AthenaJDBC](100071) An error has been thrown from the AWS Athena client. SYNTAX_ERROR: line 5:19: Unexpected parameters (time, varchar(5)) for function date_format. Expected: date_format(timestamp with time zone, varchar(x)) , date_format(timestamp, varchar(x)) [Execution ID: 89bfd858-9992-439f-ad84-b59bfd1cbde8]
Here's my code:
SELECT
column_a,
round(AVG((milliseconds) / 1000)) AS Seconds,
(case when milliseconds/1000 < 60 * 60
then time '00:00:00' + milliseconds * interval '1' second, '%i:%s'
else time '00:00:00' + milliseconds * interval '1' second, '%H:%i:%s'
end) as hhmmss,
round((AVG((column_b)) / 1099511627776),2) AS b,
COUNT(column_c) AS c
FROM
table
GROUP BY
column_a
Tried with this one as well
(case when milliseconds/1000 < 60 * 60
then date_format(time '00:00:00' + milliseconds * interval '1' second, '%i:%s')
else date_format(time '00:00:00' + milliseconds * interval '1' second, '%H:%i:%s')
end) as hhmmss
Any help, please?
You can just cast your time to timestamp:
select date_format(cast(time '00:00:00' + 23 * interval '1' second as timestamp), '%H:%i:%s')
Output:
_col0
00:00:23
Note that this will work only if you have less than 24 hours interval in your milliseconds, otherwise you will need to do math yourself and concat results into desired string.
P.S. Should not milliseconds * interval '1' second be (milliseconds/1000) * interval '1' second?

How to extract the hour of day from an epoch and count each instance that occurs during that hour?

I have a question that I feel is pretty straight forward but is giving me some issues.
I have a column in table X called event_time which is an epoch. I am wanting to extract the hour of day out of that and count the number of rides that have occurred during that hour.
So the output will end up being a bar chart with x values 0-24 and the Y being the number of instances that occur (which is bike rides for example).
Here is what I have now, that isn't giving me the correct output:
select extract(hour from to_timestamp(start_time)::date) as hr,
count(*) as ct
from x
group by hr
order by hr asc
Any hints or help are appreciated.
Thanks
You can use arithmetic:
select floor( (start_time % (24 * 60 * 60)) / (60 * 60) ) as hour,
count(*)
from x
group by hour;
Or convert to a date/time and extract the hour:
select extract(hour from '1970-01-01'::date + start_time * interval '1 second') as hour, count(*)
from x
group by hour;

Getting data that is more then or equal to in Postgres SQL query

I'm trying to write a query that uses postgres. My query needs to find the diffrence between the started_at time and now() and then only
select the data where the difference is >= 300 seconds.
Here is what I have so far
SELECT id, (extract(epoch from now()) - extract(epoch from started_at)) completed_time
FROM run_item WHERE started_at IS NOT NULL AND completed_at is NULL;
Have you tried placing this expression the where clause?
SELECT * FROM run_item WHERE
(EXTRACT(EPOCH FROM now()) - EXTRACT(EPOCH FROM started_at)) >= 300;
find the diffrence between the started_at time and now() and then only select the data where the difference is >= 300 seconds
You could do date arithmetics as follows:
select id, started_at - now() diff
from run_item r
where started_at <= now() - interval '5' minutes
In the resultset, diff is a column of interval datatype.

How to get epoch function in Oracle

select *
from sample_table scr
where extract('epoch' from systimestamp - scr.created_date)/60 > :defaultTimeOut
This is a postgres query. Trying to convert this query into oracle.
How do I convert epoch in oracle?
TIA.
You are actually trying to convert an interval (ie the difference between two dates) to a number of seconds. Assuming that created_date is of date datatype, one method is:
select *
from sample_table
where (sysdate - created_date) * 24 * 60 * 60 > :defaultTimeOut
Rationale: in Oracle, substracting two dates returns a decimal number that represents the difference in days. You can multiply that by 24 (hours per day), 60 (minutes per hour) and 60 (seconds per minute) to convert that to a number of seconds, then compare it to the target value.
If created_date is of timestamp datatype, you can cast it to a date first:
select *
from sample_table
where (sysdate - cast(created_date as date)) * 24 * 60 * 60 > :defaultTimeOut