I have a table with 3 columns Id, Data, Date.
Date has dataType timestamp with time zone.
I want to get last 5 hours created ids Query.
I tried with interval query
Select Id from table where
date > (current_date - INTERVAL '5 hour')
It is showing interval is NOT supported in postgre
How I can query to get Id for last 5 Hour
Related
I'm querying the database (RedShift) and I have a piece of information stored in epoch MS format. Envision a table along the lines of:
Purchase, date
1, 1620140227019
2, 1620140227045
3, 1620140226573
I need to convert the timestamp to a readable date but I can't make it work with to_timestamp() or extract(). The problem is first with the size of the value (13 digits are not supported).
The closest solution I have is
select to_timestamp(1620140226573/1000, 'SS')
But the result is 0051-05-04 14:57:06. In other words month, date and seconds are correct but the year is wrong.
You can run this query
select to_timestamp(round(1620140227254/1000))
The solution was in the documentation: https://docs.aws.amazon.com/redshift/latest/dg/r_Dateparts_for_datetime_functions.html
SELECT timestamp with time zone 'epoch' + 1620140227019/1000 * interval '1 second' AS converted_timestamp
or
select '1970-01-01'::date + 1620140227019/1000 * interval '1 second'
I have a table Logs with fields
Amount,date
I need to get the sum of amount and months grouped by each day
I need to migrate my sqlite code to postgresql but i find the code migration kind of hard.The sqlite code is as follows
SELECT SUM(amount),transaction_date FROM log WHERE user_id = 1 AND strftime('%Y', transaction_date) = '2019' GROUP BY strftime('%d', transaction_date);
What i need to is date and total amount grouped by day for the year 2019
You need extract() function instead of strftime() to get the year and cast transaction_date to date only if it is timestamp, if it is of data type date remove the casting ::date:
SELECT
SUM(amount),
transaction_date::date
FROM log WHERE user_id = 1 AND extract(year from transaction_date) = 2019
GROUP BY transaction_date::date
The time data in my database is stored using timestamp. I want to select a fixed time intervals from a range of days. For example, select the tuples that has timestamp that satisfies: its time is between 2pm and 3pm, and its date is between 2015-01-01 and 2015-01-31.
SELECT * FROM data WHERE ????time???? ;
In plain English select the data that are recorded between 2pm and 3pm for January.
Any suggestions?
Try
SELECT * FROM data
WHERE time_column BETWEEN date '2015-01-01' AND date '2015-01-31'
AND extract( hour from time_column ) BETWEEN 14 AND 15 ;
I'm a bit of newbie when it comes to postgres, so bear with me a wee bit and i'll see if i can put up enough information.
i insert weather data into a table every 10 mins, i have a time column that is stamped with an epoch date.
I Have a column of the last hrs rain fall, and every hr that number changes of course with the running total (for that hour).
What i would like to do is skim through the rows to the end of each hour, and get that row, but do it over the last 4 hours, so i would only be returning 4 rows say.
Is this possible in 1 query? Or should i do multiple queries?
I would like to do this in 1 query but not fussed...
Thanks
Thanks guys for your answers, i was/am a bit confused by yours gavin - sorry:) comes from not knowing this terribly well.
I'm still a bit unsure about this, so i'll try and explain it a bit better..
I have a c program that inserts data into the database every 10 mins, it reads the data fom a device that keeps the last hrs rain fall, so every 10 mins it could go up by x amount.
So i guess i have 6 rows / hr of data.
My plan was to go back (in my php page) every 7, which would be the last entry for every hour, and just grab that value. Hence why i would only ever need 4 rows.. just spaced out a bit!
My table (readings) has data like this
index | time (text) | last hrs rain fall (text)
1 | 1316069402 | 1.2
All ears to better ways of storing it too :) I very much appreciate your help too guys thanks.
You should be able to do it in one query...
Would something along the lines of:
SELECT various_columns,
the_hour,
SUM ( column_to_be_summed )
FROM ( SELECT various_columns,
column_to_be_summed,
extract ( hour FROM TIME ) AS the_hour
FROM readings
WHERE TIME > ( NOW() - INTERVAL '4 hour' ) ) a
GROUP BY various_columns,
the_hour ;
do what you need?
SELECT SUM(rainfall) FROM weatherdata WHERE time > (NOW() - INTERVAL '4 hour' );
I don't know column names but that should do it the ones in caps are pgsql types. Is that what you are after?
I am not sure if this is exactly what you are looking for but perhaps it may serve as a basis for adaptation.
I often have a requirment for producing summary data over time periods though I don't use epoch time so there may be better ways of manipulating the values than I have come up with.
create and populate test table
create table epoch_t(etime numeric);
insert into epoch_t
select extract(epoch from generate_series(now(),now() - interval '6 hours',interval '-10 minutes'));
To divide up time into period buckets:
select generate_series(to_char(now(),'yyyy-mm-dd hh24:00:00')::timestamptz,
to_char(now(),'yyyy-mm-dd hh24:00:00')::timestamptz - interval '4 hours',
interval '-1 hour');
Convert epoch time to postgres timestamp:
select timestamptz 'epoch' + etime * '1 second'::interval from epoch_t;
then truncate to hour :
select to_char(timestamptz 'epoch' + etime * '1 second'::interval,
'yyyy-mm-dd hh24:00:00')::timestamptz from epoch_t
To provide summary information by hour :
select to_char(timestamptz 'epoch' + etime * '1 second'::interval,
'yyyy-mm-dd hh24:00:00')::timestamptz,
count(*)
from epoch_t
group by 1
order by 1 desc;
If you might have gaps in the data but need to report zero results use a generate_series to create period buckets and left join to data table.
In this case I create sample hour buckets back prior to the data population above - 9 hours instead of 6 and join on the conversion of epoch time to timestamp truncated to hour.
select per.sample_hour,
sum(case etime is null when true then 0 else 1 end) as etcount
from (select generate_series(to_char(now(),
'yyyy-mm-dd hh24:00:00')::timestamptz,
to_char(now(),'yyyy-mm-dd hh24:00:00')::timestamptz - interval '9 hours',
interval '-1 hour') as sample_hour) as per
left join epoch_t on to_char(timestamptz 'epoch' + etime * '1 second'::interval,
'yyyy-mm-dd hh24:00:00')::timestamptz = per.sample_hour
group by per.sample_hour
order by per.sample_hour desc;
I have a table called items. It contains a column tz with timezone identifiers (like America/New_York, Europe/London, etc).
I want to select all the items where the current time is 8AM +/- 5 minutes.
So if I run the query at 8AM EST it will return rows where tz = 'America/New_York'.
If I run the query at 9AM EST it will return rows where tz = 'America/Chicago'.
SELECT *
FROM items
WHERE CAST(current_timestamp at time zone tz AS time) BETWEEN '07:55' AND '08:05'
You should be storing the offset for each timezone. Then the query is as simple as
select * from items where GETDATE() between
DATEADD(minute,5,DATEADD(HOUR,offset,GETUTCDATE())) and
DATEADD(minute,-5,DATEADD(HOUR,offset,GETUTCDATE()))
I'm using SqlServer GETUTCDATE and DATEADD functions, but you can easily make them work in postgresql if you lookup the correct function names.
EDIT
If you can't add a offset to the table, create a timezone table with the string timezone and numeric offset. Join and run the above query.
Your tz field is valid if it respects this: http://www.postgresql.org/docs/8.0/static/datetime-keywords.html#DATETIME-TIMEZONE-SET-TABLE
If so, I think this should work (no tested):
SELECT *
FROM items
WHERE LOCALTIMESTAMP BETWEEN
(LOCALTIMESTAMP AT TIME ZONE tz) - interval '5 minutes' AND
(LOCALTIMESTAMP AT TIME ZONE tz) + interval '5 minutes'