CASE in WHERE Clause in Snowflake - sql

I am trying to do a case statement within the where clause in snowflake but I’m not quite sure how should I go about doing it.
What I’m trying to do is, if my current month is Jan, then the where clause for date is between start of previous year and today. If not, the where clause for date would be between start of current year and today.
WHERE
CASE MONTH(CURRENT_DATE()) = 1 THEN DATE BETWEEN DATE_TRUNC(‘YEAR’, DATEADD(YEAR, -1, CURRENT_DATE())) AND CURRENT_DATE()
CASE MONTH(CURRENT_DATE()) != 1 THEN DATE BETWEEN DATE_TRUNC(‘YEAR’, CURRENT_DATE()) AND CURRENT_DATE()
END
Appreciate any help on this!


Use a CASE expression that returns -1 if the current month is January or 0 for any other month, so that you can get with DATEADD() a date of the previous or the current year to use in DATE_TRUNC():
WHERE DATE BETWEEN
DATE_TRUNC('YEAR', DATEADD(YEAR, CASE WHEN MONTH(CURRENT_DATE()) = 1 THEN -1 ELSE 0 END, CURRENT_DATE()))
AND
CURRENT_DATE()


I suspect that you don't even need to use CASE here:
WHERE
(MONTH(CURRENT_DATE()) = 1 AND
DATE BETWEEN DATE_TRUNC(‘YEAR’, DATEADD(YEAR, -1, CURRENT_DATE())) AND
CURRENT_DATE()) OR
(MONTH(CURRENT_DATE()) != 1 AND
DATE BETWEEN DATE_TRUNC(‘YEAR’, CURRENT_DATE()) AND CURRENT_DATE())


So the other answers are quite good, but... the answer can be even simpler
Making a little table to brake down what is happening.
select
row_number() over (order by null) - 1 as rn,
dateadd('day', rn * 5, date_trunc('year',current_date())) as pretend_current_date,
DATEADD(YEAR, -1, pretend_current_date) as pcd_sub1,
month(pretend_current_date) as pcd_month,
DATE_TRUNC(year, iff(pcd_month = 1, pcd_sub1, pretend_current_date)) as _from,
pretend_current_date as _to
from table(generator(ROWCOUNT => 30))
order by rn;
this shows:
RN
PRETEND_CURRENT_DATE
PCD_SUB1
PCD_MONTH
_FROM
_TO
0
2022-01-01
2021-01-01
1
2021-01-01
2022-01-01
1
2022-01-06
2021-01-06
1
2021-01-01
2022-01-06
2
2022-01-11
2021-01-11
1
2021-01-01
2022-01-11
3
2022-01-16
2021-01-16
1
2021-01-01
2022-01-16
4
2022-01-21
2021-01-21
1
2021-01-01
2022-01-21
5
2022-01-26
2021-01-26
1
2021-01-01
2022-01-26
6
2022-01-31
2021-01-31
1
2021-01-01
2022-01-31
7
2022-02-05
2021-02-05
2
2022-01-01
2022-02-05
8
2022-02-10
2021-02-10
2
2022-01-01
2022-02-10
9
2022-02-15
2021-02-15
2
2022-01-01
2022-02-15
10
2022-02-20
2021-02-20
2
2022-01-01
2022-02-20
11
2022-02-25
2021-02-25
2
2022-01-01
2022-02-25
12
2022-03-02
2021-03-02
3
2022-01-01
2022-03-02
13
2022-03-07
2021-03-07
3
2022-01-01
2022-03-07
14
2022-03-12
2021-03-12
3
2022-01-01
2022-03-12
15
2022-03-17
2021-03-17
3
2022-01-01
2022-03-17
16
2022-03-22
2021-03-22
3
2022-01-01
2022-03-22
17
2022-03-27
2021-03-27
3
2022-01-01
2022-03-27
18
2022-04-01
2021-04-01
4
2022-01-01
2022-04-01
19
2022-04-06
2021-04-06
4
2022-01-01
2022-04-06
20
2022-04-11
2021-04-11
4
2022-01-01
2022-04-11
21
2022-04-16
2021-04-16
4
2022-01-01
2022-04-16
22
2022-04-21
2021-04-21
4
2022-01-01
2022-04-21
23
2022-04-26
2021-04-26
4
2022-01-01
2022-04-26
24
2022-05-01
2021-05-01
5
2022-01-01
2022-05-01
25
2022-05-06
2021-05-06
5
2022-01-01
2022-05-06
26
2022-05-11
2021-05-11
5
2022-01-01
2022-05-11
27
2022-05-16
2021-05-16
5
2022-01-01
2022-05-16
28
2022-05-21
2021-05-21
5
2022-01-01
2022-05-21
29
2022-05-26
2021-05-26
5
2022-01-01
2022-05-26
Your logic is asking "is the current date in the month of January", at which point take the prior year, and then date truncate to the year, otherwise take the current date and truncate to the year. As the start of a BETWEEN test.
This is the same as getting the current date subtracting one month, and truncating this to year.
Thus there is no need for any IFF or CASE
WHERE date BETWEEN DATE_TRUNC(year, DATEADD(month,-1, CURRENT_DATE())) AND CURRENT_DATE()
and if you like to drop some paren's, CURRENT_DATE can be used if you leave it in upper case, thus it can even be smaller:
WHERE date BETWEEN DATE_TRUNC(year, DATEADD(month,-1, CURRENT_DATE)) AND CURRENT_DATE

Related

How to Create table with Dates in range defined by table with start date inputs

I am trying to create a dates table in SQL based on a set of inputs, but I haven't been able to figure it out.
I am receiving in SQL inputs as below:
This table:
Date
Value
2022-01-01
5
2022-07-12
10
2022-11-15
3
A Start Date = 2022-01-01
A stop Date = 2022-12-01
I need to get a table as below starting from Start Date until Stop Date, assiging each correspondent number based on the initial table to each date in that period:
Date
Value
2022-01-01
5
2022-01-02
5
2022-01-03
5
2022-01-04
5
.
5
.
5
.
5
2022-07-09
5
2022-07-10
5
2022-07-11
5
2022-07-12
10
2022-07-13
10
2022-07-14
10
.
10
.
10
2022-11-13
10
2022-11-14
10
2022-11-15
3
2022-11-16
3
2022-11-17
3
2022-11-18
3
How can I do that?
Thanks.

Using the window function lead() over() in concert with an ad-hoc tally table
Example
Select Date = dateadd(DAY,N,A.Date)
,A.Value
From (
Select *
,nDays = datediff(DAY,Date,lead(Date,1,dateadd(day,1,'2022-12-01')) over (order by date))
From YourTable
) A
Join ( Select Top 1000 N=-1+Row_Number() Over (Order By (Select NULL)) From master..spt_values n1, master..spt_values n2 ) B
on N<NDays
Order by Date
Results
Date Value
2022-01-01 5
2022-01-02 5
2022-01-03 5
2022-01-04 5
2022-01-05 5
...
2022-07-10 5
2022-07-11 5
2022-07-12 10
2022-07-13 10
2022-07-14 10
...
2022-11-12 10
2022-11-13 10
2022-11-14 10
2022-11-15 3
2022-11-16 3
2022-11-17 3
...
2022-11-30 3
2022-12-01 3

Calculate Average for Amount for certain date range in a year based on month

I have a table like below :
ID
Amount
Date
1
500
2022-01-03
1
200
2022-01-04
1
500
2022-01-05
1
340
2022-01-06
1
500
2022-01-25
1
500
2022-01-26
1
567
2022-01-27
1
500
2022-01-28
1
598
2022-01-31
1
500
2022-02-01
1
787
2022-02-02
1
500
2022-02-03
1
5340
2022-02-04
PROBLEM :-
So I have to calculate average of column where StartDate = 03/01/2022 (3rd Jan 2022) and for each month it would be like for January Average of Amount from StartDate to 25th Jan, then for Feb Startdate to 22nd Feb, so this date logic is also there
SET #Last = (SELECT DATEADD(DAY, CASE DATENAME(WEEKDAY, #Date)
WHEN 'Sunday' THEN -6
When 'Saturday' THEN -5
ELSE -7 END, DATEDIFF(DAY, 0, #Date)))
RETURN #Last
ID
Amount
Date
Last
1
500
2022-01-03
2022-01-25
1
500
2022-01-04
2022-01-25
1
340
2022-01-05
2022-01-25
1
500
2022-01-06
2022-01-25
1
567
2022-01-25
2022-01-25
1
500
2022-01-26
2022-01-25
1
500
2022-01-27
2022-01-25
1
40
2022-01-28
2022-01-25
1
500
2022-01-31
2022-01-25
1
589
2022-02-01
2022-02-22
1
540
2022-02-02
2022-02-22
1
500
2022-02-03
2022-02-22
1
5340
2022-02-04
2022-02-22
Like the above table..
Now if I calculate Avg(Amount), from 3rd jan to 25th Jan for Jan and 3rd Jan to 22nd Feb and so on.. It's not giving correct average, like it is calculating the rest of the days amount also. Also grouping by is grouping month wise not as where clause
Select Avg(Amount) from Table
where Date BETWEEN #StartDate AND Last
StartDate is fixed # 3rd Jan.
This is not giving the correct Avg. Any other way I could get the required data?

Select data between 2 datetime fields based on current date/time

I have a table that has the following values (reduced for brevity)
Period
Periodfrom
Periodto
Glperiodoracle
Glperiodcalendar
88
2022-01-01 00:00:00
2022-01-28 00:00:00
JAN-FY2022
JAN-2022
89
2022-01-29 00:00:00
2022-02-25 00:00:00
FEB-FY2022
FEB-2022
90
2022-02-26 00:00:00
2022-04-01 00:00:00
MAR-FY2022
MAR-2022
91
2022-04-02 00:00:00
2022-04-29 00:00:00
APR-FY2022
APR-2022
92
2022-04-30 00:00:00
2022-05-27 00:00:00
MAY-FY2022
MAY-2022
93
2022-05-28 00:00:00
2022-07-01 00:00:00
JUN-FY2022
JUN-2022
94
2022-07-02 00:00:00
2022-07-29 00:00:00
JUL-FY2022
JUL-2022
95
2022-07-30 00:00:00
2022-08-26 00:00:00
AUG-FY2022
AUG-2022
96
2022-08-27 00:00:00
2022-09-30 00:00:00
SEP-FY2022
SEP-2022
97
2022-10-01 00:00:00
2022-10-28 00:00:00
OCT-FY2023
OCT-2022
I want to make a stored procedure that when executed (without receiving parameters) will return the single row corresponding to the date between PeriodFrom and PeriodTo based on execution date.
I have something like this:
Select top 1 Period,
Periodfrom,
Periodto,
Glperiodoracle,
Glperiodcalendar
From Calendar_Period
Where Periodfrom <= getdate()
And Periodto >= getdate()
I understand that using BETWEEN could lead to errors, but would this work in the edge cases taking in account seconds, right?

Looks like (i) your end date is inclusive (ii) the time portion is always 00:00. So the correct and most performant query would be:
where cast(getdate() as date) between Periodfrom and Periodto
It will, for example, return the first row when the current time is 2022-01-28 23:59:59.999.

check if the person have pervious record with certain date :db2 sql

i have the following table :
id name start end
1 Asla 2021-01-01 2021-12-31
1 Asla 2022-01-01 2022-04-15
2 Tina 2021-05-16 2021-09-23
3 Layla 2021-01-01 2021-09-27
3 Layla 2022-01-01 2022-07-18
2 Sim 2020-05-12 2020-08-13
3 Anderas 2021-07-01 2021-09-13
3 Anderas 2021-10-01 2021-11-18
3 Anderas 2022-01-01 2029-11-18
4 Klara 2022-01-01 null
what i want to do get persons that have work (date) under 2021 and create a new column that show status (if the person continue having work under 2022 -- ok else not ok and if the person is new like 'Klara' get new ) and show last record for every person . maybe too End = null ??????
i tried this .
select w.id ,w.name ,w.start ,w.end, max_date.end
from Work_date w
left join (select * from Work_date where start>='2022-01-01')max_date on max_date.id=id
where w.start>='2021-01-01'
``` but the problem i get the result as this
<pre>
id name start end
1 Asla 2021-01-01 null
1 Asla 2022-01-01 2022-04-15
2 Tina 2021-05-16 null
3 Layla 2021-01-01 null
3 Layla 2022-01-01 2022-07-18
3 Anderas 2021-07-01 null
3 Anderas 2021-10-01 2021-11-18
3 Anderas 2022-01-01 null
4 Klara 2022-01-01 null
</pre>
men i want to get result as <pre>
id name start end status
1 Asla 2022-01-01 2022-04-15 ok
2 Tina 2021-05-16 2021-09-23 not ok
3 Layla 2022-01-01 2022-07-18 ok
3 Anderas 2022-01-01 2029-11-18 ok
4 Klara 2022-01-01 null ok

Looks like you can simply aggregate.
Then use a CASE WHEN for the status.
select
w.id
, w.name
, max(w.start) as start
, max(w.end) as end
, case
when year(max(end)) < 2022 then 'not ok'
else 'ok'
end as status
from Work_date w
where w.start >= '2021-01-01'
group by w.id, w.name
order by w.id, max(w.start), max(w.end);
ID
NAME
START
END
STATUS
1
Asla
2022-01-01
2022-04-15
ok
2
Tina
2021-05-16
2021-09-23
not ok
3
Layla
2022-01-01
2022-07-18
ok
3
Anderas
2022-01-01
2029-11-18
ok
4
Klara
2022-01-01
null
ok
Demo on db<>fiddle here

Get quarter start/end dates for more than a year (start year to current year)

I've been trying to get start and end dates range for each quarter given a specific date/year, like this:
SELECT DATEADD(mm, (quarter - 1) * 3, year_date) StartDate,
DATEADD(dd, 0, DATEADD(mm, quarter * 3, year_date)) EndDate
--quarter QuarterNo
FROM
(
SELECT '2012-01-01' year_date
) s CROSS JOIN
(
SELECT 1 quarter UNION ALL
SELECT 2 UNION ALL
SELECT 3 UNION ALL
SELECT 4
) q
which produces the following output:
2012-01-01 00:00:00 2012-04-01 00:00:00
2012-04-01 00:00:00 2012-07-01 00:00:00
2012-07-01 00:00:00 2012-10-01 00:00:00
2012-10-01 00:00:00 2013-01-01 00:00:00
Problem: I need to do this for a given start_date and end_date, the problem being the end_date=current_day, so how can I achieve this:
2012-01-01 00:00:00 2012-04-01 00:00:00
2012-04-01 00:00:00 2012-07-01 00:00:00
2012-07-01 00:00:00 2012-10-01 00:00:00
2012-10-01 00:00:00 2013-01-01 00:00:00
... ...
2021-01-01 00:00:00 2021-01-06 00:00:00

I think here is what you want to do :
SET startdatevar AS DATEtime = '2020-01-10'
;WITH RECURSIVE cte AS (
SELECT startdatevar AS startdate , DATEADD(QUARTER, 1 , startdatevar) enddate , 1 quarter
UNION ALL
SELECT enddate , CASE WHEN DATEADD(QUARTER, 1 , enddate) > CURRENT_DATE() THEN GETDATE() ELSE DATEADD(QUARTER, 1 , enddate) END enddate, quarter + 1
FROM cte
WHERE
cte.enddate <= CURRENT_DATE()
and quarter < 4
)
SELECT * FROM cte
to use your code , if you want to have more than 4 quarters :
SET quarter_limit = DATEDIFF(quarter , <startdate>,<enddate>)
;WITH RECURSIVE cte(q, qDate,enddate) as
(
select 1,
DATEFROMPARTS(year('2012-01-01'::date), 1, 1) -- First quarter date
,time_slice('2012-01-01'::date, 3, 'MONTH', 'END')
UNION ALL
select q+1,
DATEADD(q, 1, qdate) -- next quarter start date
,time_slice(qdate::date, (q+1)*3, 'MONTH', 'END')
from cte
where q < quarter_limit -- limiting the number of next quarters
AND cte.endDate <= <enddate>
)
SELECT * FROM cte

After #eshirvana's answer, I came up with this slightly change after your answer:
WITH RECURSIVE cte(q, qDate,enddate) as
(
select 1,
DATEFROMPARTS(year('2012-01-01'::date), 1, 1) -- First quarter date
,time_slice('2012-01-01'::date, 3, 'MONTH', 'END')
UNION ALL
select q+1,
DATEADD(q, 1, qdate) -- next quarter start date
,time_slice(qdate::date, (q+1)*3, 'MONTH', 'END')
from cte
where q <4 -- limiting the number of next quarters
AND cte.endDate <= CURRENT_DATE()
)
SELECT * FROM cte
Which works fine for whatever year I pass there (2012 will produce 4 records, 2021 just one, since we're still on the first quarter right now).
[EDIT]: it still doesn't work as expected after your 2nd code sugestion:
WITH RECURSIVE cte(q, qDate,enddate) as
(
select 1,
DATEFROMPARTS(year('2012-01-01'::date), 1, 1) -- First quarter date
,CASE WHEN time_slice('2012-01-01'::date, 3, 'MONTH', 'END') > CURRENT_DATE
THEN current_date
ELSE time_slice('2012-01-01'::date, 3, 'MONTH', 'END')
END
UNION ALL
select q+1,
DATEADD(q, 1, qdate) -- next quarter start date
,time_slice(qdate::date, (q+1)*3, 'MONTH', 'END')
from cte
where q < DATEDIFF(quarter , '2012-01-01'::date,'2021-01-06'::date)
AND cte.endDate <= '2021-01-06'::date
)
SELECT * FROM cte
is outputing this:
Sorry #eshirvana, it doesn't work as expected though. It all goes well to some point, but it's not returning all the records. Instead, it produces less records and wrong one, like this:
1 2012-01-01 2012-04-01
2 2012-04-01 2012-07-01
3 2012-07-01 2012-10-01
4 2012-10-01 2013-01-01
5 2013-01-01 2013-10-01
6 2013-04-01 2013-07-01
7 2013-07-01 2013-10-01
8 2013-10-01 2014-01-01
9 2014-01-01 2015-01-01
10 2014-04-01 2015-01-01
11 2014-07-01 2016-10-01
12 2014-10-01 2015-01-01
13 2015-01-01 2015-07-01
14 2015-04-01 2015-07-01
15 2015-07-01 2018-10-01
16 2015-10-01 2018-01-01
17 2016-01-01 2016-10-01
18 2016-04-01 2019-07-01
19 2016-07-01 2017-07-01
20 2016-10-01 2020-01-01
21 2017-01-01 2017-04-01
22 2017-04-01 2019-07-01
23 2017-07-01 2021-10-01
Although my logic it's still not ok for not printing just Q1 dates for 2021, could this output issues be related to date format or something?

Now, it seems to be working, at least for 2012-01-01 till today (2021-01-06).
The code :
WITH RECURSIVE cte(q, qDate,enddate) as
(
select
-- it might not be the first quarter, so better to protect that:
quarter('2012-01-01'::date)::numeric
, DATEFROMPARTS(year('2012-01-01'::date), 1, 1) -- First quarter date
, CASE WHEN time_slice('2012-01-01'::date, 3, 'MONTH', 'END') > '2021-01-06'::date
THEN '2021-01-06'::date
ELSE time_slice('2012-01-01'::date, 3, 'MONTH', 'END')
END
UNION ALL
select q+1
, DATEADD(q, 1, qdate) -- next quarter start date
,CASE WHEN time_slice(DATEADD(q, 1, qdate), 3, 'MONTH', 'END')> '2021-01-06'::date
THEN '2021-01-06'::date
ELSE time_slice(DATEADD(q, 1, qdate), 3, 'MONTH', 'END')
END
from cte
where q <= DATEDIFF(quarter , '2012-01-01'::date,'2021-01-06'::date)
AND cte.endDate <= '2021-01-06'::date
)
SELECT * FROM cte
The output:
1 2012-01-01 2012-04-01
2 2012-04-01 2012-07-01
3 2012-07-01 2012-10-01
4 2012-10-01 2013-01-01
5 2013-01-01 2013-04-01
6 2013-04-01 2013-07-01
7 2013-07-01 2013-10-01
8 2013-10-01 2014-01-01
9 2014-01-01 2014-04-01
10 2014-04-01 2014-07-01
11 2014-07-01 2014-10-01
12 2014-10-01 2015-01-01
13 2015-01-01 2015-04-01
14 2015-04-01 2015-07-01
15 2015-07-01 2015-10-01
16 2015-10-01 2016-01-01
17 2016-01-01 2016-04-01
18 2016-04-01 2016-07-01
19 2016-07-01 2016-10-01
20 2016-10-01 2017-01-01
21 2017-01-01 2017-04-01
22 2017-04-01 2017-07-01
23 2017-07-01 2017-10-01
24 2017-10-01 2018-01-01
25 2018-01-01 2018-04-01
26 2018-04-01 2018-07-01
27 2018-07-01 2018-10-01
28 2018-10-01 2019-01-01
29 2019-01-01 2019-04-01
30 2019-04-01 2019-07-01
31 2019-07-01 2019-10-01
32 2019-10-01 2020-01-01
33 2020-01-01 2020-04-01
34 2020-04-01 2020-07-01
35 2020-07-01 2020-10-01
36 2020-10-01 2021-01-01
37 2021-01-01 2021-01-06
In case you're wondering: yes, the idea is to present the end_date as last_day of the month+one. But it could easily be adapted.
It's not pretty, but I think it's somehow easy to understand.