select dates between two unix timestamps - postgresql

I have the table users.
Columns:
user_id - integer
user_date - integer(unix timestamp)
Some of rows have user_date and some have NULL.
I need to find all user_id's which user_date includes period between '2012-10-21' and '2012-10-24'

SELECT *
FROM users
WHERE user_date BETWEEN
EXTRACT(EPOCH FROM date '2012-10-21') AND
EXTRACT(EPOCH FROM date '2012-10-24' + interval '1 day');
If you don't want the end date to be included, remove the bit adding a day to that.

select *
from users
where
timestamp 'epoch' + user_date * interval '1 second' between '2012-10-21' and '2012-10-24'
and
user_date is not null

Related

Postgres select date on the basis of interval array

I required a custom solution to a problem in which users can choose a number of different intervals for data comparisons.
Example:
CURRENT_DATE - interval '1 day'
CURRENT_DATE - interval '4 day'
CURRENT_DATE - interval '7 day'
AND so on
So I am looking for a solution in which I can pass the array of integers in intervals like
select CURRENT_DATE - interval '1day' * any(ARRAY[1,4,7])
But it is not possible because
op ANY/ALL (array) requires an operator to yield boolean
demos:db<>fiddle
You can use unnest() to extract the array elements into one record per element and then return the CURRENT_DATE minus each of these elements:
SELECT
CURRENT_DATE - array_element
FROM unnest(ARRAY[1,4,7]) as array_element
Naturally, you can put the unnest() into the SELECT list:
SELECT CURRENT_DATE - unnest(ARRAY[1,4,7])
Edit:
If you need another date range than days you can use intervals for that:
SELECT CURRENT_DATE - unnest(ARRAY[1,4,7]) * interval '1 week'

Postgresql difference in time based on interval

I have a table, time_slots, which has a column start_time. My users table has a column, hours_before (int), which is the number of hours before the start_time to receive a notification.
I'm running a job every 5 minutes that checks the time slots that have a start_time which is now + hours_before. All my datetimes are store in UTC. I can't figure out the correct where clause to get the appropriate time slots.
Right now I'm passing in the current time in UTC as a string rather than doing something like current_timestamp at time zone 'UTC'.
(extract(epoch from starts_at) - extract(epoch from (date '2020-11-09 06:20:00' + (users.hours_before * INTERVAL '1 hour')))) = 0
Here is a test query to see what the values are inside of a select. In this example, (6 * INTERVAL '1 hour') would be where users.hours_before would be. I'm using a static 6 while tinkering.
select
(extract(epoch from "starts_at") - extract(epoch from date '2020-11-09 06:20:00')) / 3600 as hours,
(extract(epoch from "starts_at") - extract(epoch from (date '2020-11-09 06:20:00' + (6 * INTERVAL '1 hour')))) as other_interval,
*
from
"time_slots"
where
"starts_at" > '2020-11-09 06:20:00'
order by hours asc;
For example, the following query has the same hours and other_interval values as the above query, despite the date being 2020-11-09 10:00:00 instead of 2020-11-09 06:00:00. Shouldn't those columns be 4 hours different since they change by 4 hours?
select
(extract(epoch from "starts_at") - extract(epoch from date '2020-11-09 10:00:00')) / 3600 as hours,
(extract(epoch from "starts_at") - extract(epoch from (date '2020-11-09 10:00:00' + (6 * INTERVAL '1 hour')))) as other_interval,
*
from
"time_slots"
where
"starts_at" >= '2020-11-09 06:00:00'
order by hours asc;

PostgreSQL - Difference between Current Date and a Date from Database

I'm trying to make a SELECT query which will compare current time with time at database. For example in database there is a record '2018-02-07 12:00:00' and I wanna compare it to current time. If current time is '2018-02-07 11:00:00', record '2018-02-07 12:00:00' should be visible in results. It should compare two dates and shows only those who are 1h before or after current time.'
Tried something like this:
SELECT * FROM events WHERE age(current_date, event_date) < '1 hour';
or
SELECT * FROM events WHERE event_date > (now() - INTERVAL '1 hour');
those that are 1h before or after current time
Wouldn't the logic look like this?
SELECT e.*
FROM events e
WHERE e.event_date > now() - INTERVAL '1 hour' AND
e.event_date < now() + INTERVAL '1 hour'

How define today date with Default timestmp

I am using postgressql i wish to get the data for currentdate, i want filter the data based on the date
in data base my plandate filed is define as Time stamp with time zone so its showing like this format 2013-09-01 03:22:01.438348+05:30 my query is like this
select ttodoid ,date,details from ttodo where date=currentdate():
but currentdate function giving me just date '2013-10-06' based on this result is no rows how can i manage it for today date detail
UPDATED: One way to do it
SELECT *
FROM ttodo
WHERE date BETWEEN DATE_TRUNC('day', CURRENT_TIMESTAMP)
AND DATE_TRUNC('day', CURRENT_TIMESTAMP)
+ INTERVAL '1 DAY'
- INTERVAL '1 MICROSECOND';
or
SELECT *
FROM ttodo
WHERE date >= DATE_TRUNC('day', CURRENT_TIMESTAMP)
AND date < DATE_TRUNC('day', CURRENT_TIMESTAMP)
+ INTERVAL '1 DAY';
Here is SQLFiddle demo
select * from ttodo where (ttodo.todoplandate::date = current_date) or
(ttodo.todoplandate::date < current_date
I think the easier approach would be just to convert your field to date:
SELECT ttodoid ,date,details FROM ttodo
WHERE CAST(date AS DATE) = current_date;
Notice that, ff you want this query to be indexed, you have to create the index with the cast:
CREATE INDEX idx_ttodo_date ON ttodo ((CAST(date AS DATE)));
Another approach, is instead of casting the field, is checking the intervals, something similar of what petern proposed, but with correct intervals:
SELECT ttodoid ,date,details FROM ttodo
WHERE date >= date_trunc('day', current_timestamp)
AND date < (date_trunc('day', current_timestamp) + interval '1day');
This approach has the advantage that it can use an index on the date field only, which is good if you already have it.

get last three month records from table

How to get last 3 months records from the table.
SELECT *
from table
where month > CURRENT_DATE-120
and month < CURRENT_DATE
order by month;
I have used the above query is it correct? shall I use this for get last 3 month record from the table.
You can use built-in INTERVAL instruction
Check how this works:
SELECT CURRENT_DATE - INTERVAL '3 months'
and you can rewrite your SQL to:
SELECT * from table where date > CURRENT_DATE - INTERVAL '3 months'
(not checked but this should give you an idea how to use INTERVAL instruction)
Try that:
SELECT *
FROM table
WHERE month BETWEEN EXTRACT(MONTH FROM NOW() - INTERVAL '3 months')
AND EXTRACT(MONTH FROM NOW())
ORDER BY month
;
This filters the last 3 calendar months
SELECT * from table where date >= to_char(CURRENT_DATE - INTERVAL '3 months', 'YYYY-MM-01')::date
select date::date
from generate_series((current_date - INTERVAL '1 Month')::date, (current_date - INTERVAL '1 DAY')::date,'1
day'::interval) date
WHERE date >= date_trunc('month', current_date - interval '3' month)
and date < date_trunc('month', current_date)
This will give last three months date list, excluding current months date. Example if current month is November. This list will give use all dates of August, Septemeber and October.