How to run a query for every date for last 3 month - sql

I have a table(pkg_date) in redshift. I want to fetch some data for every date for the last 3 months.
Here is my query
select * from pkg_data where scan_date < current_date;
How can I use current_date as a variable in the query itself and run this query for every date from April 1.
I have set a cron job which will run in every hour. In every hour it should run with different current_date

SELECT *
FROM pkg_data
WHERE scan_date > CURRENT_DATE - INTERVAL '3 months'
Be careful — Redshift works in UTC, so the CURRENT_DATE might suffer from timezone effects and be +/- what you expect sometimes.
SELECT
CURRENT_DATE,
(CURRENT_DATE - INTERVAL '3 months')::date
Returns:
2018-06-21 2018-03-21
Also be careful with strange lengths of months!
SELECT DATE '2018-05-31' - INTERVAL '3 months'
returns:
2018-02-28 00:00:00
Notice that it gave the last day of the month (31st vs 28th).
By the way, you can use DATE '2018-05-31' or '2018-05-31'::DATE, and also INTERVAL '3 months' or '3 months'::INTERVAL to convert types.

Use dateadd() for getting date 3 moth old day and GETDATE() for get current date.
ie code will look like.
select * from pkg_data where scan_date < dateadd(month,-3,GETDATE());
for cron refer How to execute scheduled SQL script on Amazon Redshift?

Related

Hive Date and Week Functions Migration From Greenplum Query

Could you please help me as below statement , i want to migrate from Greenplum to HiveSQL. kindly help me.
(date_trunc('week',idate) - INTERVAL '1 week')::DATE date_from
((date_trunc('week',idate) - INTERVAL '1 week')::DATE + '6 days'::INTERVAL)::DATE
date_trunc('week',idate)::DATE
note: idate is i have to parse the argument like 2021-02-20
If you are looking to
find start of week then use select next_day(date_sub(current_date, 7), 'MON')
add 1 week to the date then use select current_date + interval 7 day
convert date to string then use select to_date(current_date )
Now, from your code, it seems, you are looking for start of week and then deducting 1 week from that.
(date_trunc('week',idate) - INTERVAL '1 week')
This can be re-written in hive like below.
next_day(date_sub(current_date, 7), 'MON') - interval 7 day
I assumed Monday is your start of week. Please validate the SQL before using it.

Incrementing Date - SQL(Snowflake)

I want to Increment/Decrement the Year , Day , Month by pulling in the Current Date in Snowflake in a single query ?
For e.g.
Suppose Current System Date - 04082021 I want to make it 05092022. I have tried the dateadd function but I suppose it allows only one part i.e. either year or month or day to be incremented at once.
Is it Possible ? If Not, What are the other alternatives ?
If you want to useDATEADD function, here is the code:
SELECT DATEADD(YEAR,+1,DATEADD(MONTH,+1,DATEADD(DAY,+1,CURRENT_DATE())));
returns 2022-09-05 from 2021-08-04
If you want to keep your format, Please use following code
SELECT TO_CHAR(DATEADD(YEAR,+1,DATEADD(MONTH,+1,DATEADD(DAY,+1,CURRENT_DATE()))),'DDMMYYYY');
I would do the arithmetic in thee parts:
select current_date + interval '1 year' + interval '1 month' + interval '1 day'
You can also use:
select current_date + interval '1 year, 1 month, 1 day'

Presto TIMESTAMP get data from 2 days ago without inputting year month date?

My goal is to have the query grab data from 2 days ago. I don't want to have to keep inputting the date like this:
WHERE usage_start_date
BETWEEN TIMESTAMP '2020-09-09 00:00:00.000' and TIMESTAMP '2020-09-09
23:59:59.999'
but instead something like:
usage_start_date = current_date - interval '2' day
the above works for my Athena Presto SQL query, but for some reason will not give all the data that ran in those 24 hours, instead giving about half the day. Is there a way to do a statement like this one to ensure it gives ALL data in that day?
WHERE current_date - interval '2' day AND
BETWEEN TIMESTAMP '00:00:00.000' and TIMESTAMP '23:59:59.999'
without inputting the year, month, day? It seems like TIMESTAMP needs the y/m/d but what about doing a LIKE so it picks up the hour, minute, second but no need to put the y/m/d?
To get a timestamp for the start of the day that was two days ago you can do
DATE_TRUNC('day', NOW() - INTERVAL '2' DAY)
e.g.
WHERE usage_start_date >= DATE_TRUNC('day', NOW() - INTERVAL '2' DAY)
AND usage_start_date < DATE_TRUNC('day', NOW() - INTERVAL '1' DAY)
You can use below query to achieve the task by fetching the hour and date from the usage_start_date
select * from table where hour(usage_start_date) between 0 and 23 and current_date - interval '2' day = date(usage_start_date)
I would suggest:
WHERE usage_start_date >= CURRENT_DATE - INTERVAL '2' DAY AND
usage_start_date < CURRENT_DATE - INTERVAL '1' DAY

Between Operator Big Query Standard SQL

Using Standard SQL in BQ - as part of a task I want to search for records created between 2pm the previous day & 2pm on current day
I have found
SELECT DATETIME_SUB(DATETIME_TRUNC(CURRENT_DATETIME(), DAY), INTERVAL 10 hour) Gives me 2PM yesterday
SELECT DATETIME_ADD(DATETIME_TRUNC(CURRENT_DATETIME(), DAY), INTERVAL 14 hour)
Gives me 2pm today
So, i assumed i could use this in my query
Select * from
TableA
where CreatedDate Between
DATETIME_SUB(DATETIME_TRUNC(CURRENT_DATETIME(), DAY), INTERVAL 10 hour) and DATETIME_ADD(DATETIME_TRUNC(CURRENT_DATETIME(), DAY), INTERVAL 14 hour)
However I get the following
No matching signature for operator BETWEEN for argument types:
TIMESTAMP, DATETIME, DATETIME. Supported signature: (ANY) BETWEEN
(ANY) AND (ANY)
Where am i going wrong?
Your issue is that CreatedDate is TIMESTAMP and you need to convert into a DATETIME
It could be like:
where DATETIME(CreatedDate) Between ...
But you could easily write your own statements for TIMESTAMP
SELECT timestamp_sub(timestamp_trunc(current_timestamp() ,
DAY),interval 10 hour)

Get the timestamp of a day of the week

I am trying to find the timestamp of a certain day of the week with postgrSQL. For example, one might use now() to get the current time, but I want to get the same type of data return for, say, the most recent Monday or Sunday.
I am looking for this because I have a query which retrieves data between now and a few months ago and I don't want to include the current week. As an example what it does now:
creation_date > now() - INTERVAL '2 month'
I thought this might achieve my goals:
BETWEEN now() - INTERVAL '4 month' AND now() - INTERVAL '1 week'
But it just subtracts 7 days from the query which is not what I want. Basically, I want:
BETWEEN now() - INTERVAL '4 month' AND ????
Where the question marks are timestamp for the most recent Sunday, at least I believe that would work.
date_trunc('week', current_date) - interval '1' day
date_trunc('week', current_date) will return the date at the start of the week.
The start of the week is always Monday in Postgres. That's why you need to subract another day from the result to get the Sunday.
You can extract the current day of the week (0-6, Sunday is 0) using EXTRACT(DOW FROM date). You could then use this to create an interval to add or subtract to reach a particular weekday. For example, the most recent Sunday would be now() - (EXTRACT(DOW FROM now()) || ' days')::interval.