I have a list of start dates as below -
start dates sorted in descending order
The start dates are always sorted in descending order.
I am looking for a postgresql query that can give the following output -
start dates with groups
Basically i am trying to create groups of dates from the given list such that each date in a group is within 61 days from the date at the top of the corresponding group.
For example -
in the output,
Group 1 has first 4 records because all 4 start dates are within 61
days of record no. 2.
Group 2 contains only record no. 6 since it is more than 61 days
away from record no. 2.
Group 3 contains row no. 7 and 8 since they are more than 61
days away from record no. 6. but within 61 days of each other
P.S. I am new to postgresql and stackoverflow.
Any pointers will be helpfull
Your sample data does not match your sample output.
Your calculations in your sample output are wrong since this counts backwards and March and October both have 31 days.
To recurse properly you need to assign row numbers using dense_rank():
with recursive num as (
select row_number() over (order by start_date desc) as rn,
start_date
from dateslist
),
Then you create groups and find gaps by carrying anchor values forward as you recurse. Since you have the start_date information you can calculate the offset within groups at the same time:
find_gaps as (
select rn as anchor, start_date as anchor_date, rn, start_date, 0 as group_offset
from num
where rn = 1
union all
select case
when f.anchor_date - n.start_date > 61 then n.rn
else f.anchor
end,
case
when f.anchor_date - n.start_date > 61 then n.start_date
else f.anchor_date
end,
n.rn, n.start_date,
case
when f.anchor_date - n.start_date > 61 then n.start_date
else f.anchor_date
end - n.start_date
from find_gaps f
join num n on n.rn = f.rn + 1
)
The final query selects the columns you want for the output and applies a group number.
select start_date,
dense_rank() over (order by anchor) as group_number,
group_offset
from find_gaps
order by start_date desc;
Working Fiddle Demo
Related
I am running an analysis on medication prescribing practices. We want to identify whether someone has been on a class of medications for 60 days out of a 90 day quarter. We have a start and end date for each prescription, and the bounds of the quarter (e.g., 4/1/2022 – 6/30/2022). For each prescription I’ve calculated the number of days between the start and end date (only including days that fall within the bounds of the quarter). There are many instances in which multiple drugs within the same class are prescribed someone might try one antidepressant but not like it, so be given another in the same class.
My original strategy was just to total up number of days for each class of medication and see if it’s 60 or over. The days don’t have to be consecutive, but if they overlap, days during an overlap period shouldn’t count twice (which they would in a simple sum).
For instance in the data table below, patient 1 in row 1 should be included as they are over 60 days. Patient 2 should also get in (rows 2 and 3) because the non-overlapping total (57+8) within the same med class gets them to over 60 days. However, patient 3 should NOT get in, even though the total of 32 + 32 is over 60 because the intervals overlap. This means that they were really on the medication class for only 32 days – this is an instance where someone might be on two different antidepressants simultaneously.
It’s not sufficient to just sum the days in the interval, but I also have to include some way to examine whether the intervals are overlapping and only add days if an interval for a given medication class falls outside another interval for that same class.
Row num Patid Med class Start date End date Interval
1 1 A 2022-04-28 2022-09-12 63
2 2 B 2022-05-03 2022-06-29 57
3 2 B 2022-04-21 2022-04-29 8
4 3 A 2022-01-19 2022-05-03 32
5 3 A 2022-01-19 2022-05-03 32
I’m having a hard time figuring out how to do this. Note, I'm limited to just using SQL for this.
Code that produced the above data. I would embed this in another query to generate a total interval but need to deal with the overlap issue.
DECLARE #startdt DATE;
DECLARE #enddt DATE;
SET #startdt='4/1/2022'
SET #enddt='6/30/2022'
--for q4 fy2022-23 (4/1/2022-6/30/2022)`
SELECT DISTINCT
rx.patid, d.medication_category as medcat, start_date, end_date,
-- case statement to capture days within quarter only
CASE WHEN start_date<#startdt and end_date>#enddt then 90
WHEN start_date<#startdt and end_date>=#startdt then datediff(d,#startdt,end_date)
WHEN start_date>=#startdt and end_date>#enddt then datediff(d,start_date,#enddt)
ELSE datediff(d,start_date,end_date)
END as interval
FROM rx
INNER JOIN Drug_names_categories d
ON rx.drugname=d.drugname
WHERE start_date<'7/1/2022' and end_date>'3/30/2022'
AND rx.patid IS NOT NULL
AND d.medication_category IS NOT NULL
AND d.medication_category <>''
You can accomplish what you want by generating a calendar table (using a Common Table Expression) of individual days within the test range, joining those days with the prescriptions with overlapping days, and then counting distinct days for each patient and medication category combination.
Something like:
DECLARE #startdt DATE = '2022-04-01';
DECLARE #enddt DATE = '2022-06-30';
DECLARE #threshold INT = 60;
WITH Days AS (
SELECT #startdt AS Day
UNION ALL
SELECT DATEADD(day, 1, Day)
FROM Days
WHERE Day < #enddt
)
SELECT
rx.patid, d.medication_category as medcat,
COUNT(DISTINCT DD.Day) AS days_medicated,
MIN(DD.Day) AS start_date,
MAX(DD.Day) AS end_date
FROM rx
INNER JOIN Drug_names_categories d
ON rx.drugname = d.drugname
INNER JOIN Days DD
ON DD.Day BETWEEN rx.start_date AND rx.end_date
WHERE rx.start_date <= #enddt AND #startdt <= rx.end_date
GROUP BY rx.patid, d.medication_category
HAVING COUNT(DISTINCT DD.Day) >= #threshold
ORDER BY rx.patid, start_date;
If using SQL Server 2022 or later, the Days generator can be simplified by using the new GENERATE_SERIES() function:
WITH Days AS (
SELECT DATEADD(day, S.value, #startdt) AS Day
FROM GENERATE_SERIES(0, DATEDIFF(day, #Startdt, #enddt)) S
)
See this db<>fiddle for an example with some sample data.
I would do this using a date/calendar table, then it's pretty easy.
If you don't already have a date table, this link is one of many that describe how to create one easily ( https://www.mssqltips.com/sqlservertip/4054/creating-a-date-dimension-or-calendar-table-in-sql-server/ )
Here's the script from this link (in case the link dies)
DECLARE #StartDate date = '20100101';
DECLARE #CutoffDate date = DATEADD(DAY, -1, DATEADD(YEAR, 30, #StartDate));
;WITH seq(n) AS
(
SELECT 0 UNION ALL SELECT n + 1 FROM seq
WHERE n < DATEDIFF(DAY, #StartDate, #CutoffDate)
),
d(d) AS
(
SELECT DATEADD(DAY, n, #StartDate) FROM seq
),
src AS
(
SELECT
TheDate = CONVERT(date, d),
TheDay = DATEPART(DAY, d),
TheDayName = DATENAME(WEEKDAY, d),
TheWeek = DATEPART(WEEK, d),
TheISOWeek = DATEPART(ISO_WEEK, d),
TheDayOfWeek = DATEPART(WEEKDAY, d),
TheMonth = DATEPART(MONTH, d),
TheMonthName = DATENAME(MONTH, d),
TheQuarter = DATEPART(Quarter, d),
TheYear = DATEPART(YEAR, d),
TheFirstOfMonth = DATEFROMPARTS(YEAR(d), MONTH(d), 1),
TheLastOfYear = DATEFROMPARTS(YEAR(d), 12, 31),
TheDayOfYear = DATEPART(DAYOFYEAR, d)
FROM d
)
SELECT *
INTO MyDateTable
FROM src
ORDER BY TheDate
OPTION (MAXRECURSION 0);
No that you have your new date table you can join to it to get the list of dates that are within the start and end date, something like
SELECT DISTINCT COUNT(TheDate)
FROM rx
INNER JOIN MyDateTable dt on dt BETWEEN rx.start_date AND rx.end_date
INNER JOIN Drug_names_categories d ON rx.drugname=d.drugname
WHERE start_date<'7/1/2022' and end_date>'3/30/2022'
AND rx.patid IS NOT NULL
AND d.medication_category IS NOT NULL
AND d.medication_category <>''
Obviously this is simple example but you could extend this easily to include all the details you need, the point is that you now have a list of dates or distinct list of dates which you can work with easily.
You could also simply the date range applied by referencing the TheQuarter and TheYear columns. If this is a common task consider extending the date table to contain a comound YearQurater columns (e.g. 2023Q1/202301 etc)
I am working on a query to return the next 7 days worth of data every time an event happens indicated by "where event = 1". The goal is to then group all the data by the user id and perform aggregate functions on this data after the event happens - the event is encoded as binary [0, 1].
So far, I have been attempting to use nested select statements to structure the data how I would like to have it, but using the window functions is starting to restrict me. I am now thinking a self join could be more appropriate but need help in constructing such a query.
The query currently first creates daily aggregate values grouped by user and date (3rd level nested select). Then, the 2nd level sums the data "value_x" to obtain an aggregate value grouped by the user. Then, the 1st level nested select statement uses the lead function to grab the next rows value over and partitioned by each user which acts as selecting the next day's value when event = 1. Lastly, the select statement uses an aggregate function to calculate the average "sum_next_day_value_after_event" grouped by user and where event = 1. Put together, where event = 1, the query returns the avg(value_x) of the next row's total value_x.
However, this doesn't follow my time rule; "where event = 1", return the next 7 days worth of data after the event happens. If there is not 7 days worth of data, then return whatever data is <= 7 days. Yes, I currently only have one lead with the offset as 1, but you could just put 6 more of these functions to grab the next 6 rows. But, the lead function currently just grabs the next row without regard to date. So theoretically, the next row's "value_x" could actually be 15 days from where "event = 1". Also, as can be seen below in the data table, a user may have more than one row per day.
Here is the following query I have so far:
select
f.user_id
avg(f.sum_next_day_value_after_event) as sum_next_day_values
from (
select
bld.user_id,
lead(bld.value_x, 1) over(partition by bld.user_id order by bld.daily) as sum_next_day_value_after_event
from (
select
l.user_id,
l.daily,
sum(l.value_x) as sum_daily_value_x
from (
select
user_id, value_x, date_part('day', day_ts) as daily
from table_1
group by date_part('day', day_ts), user_id, value_x) l
group by l.user_id, l.day_ts
order by l.user_id) bld) f
group by f.user_id
Below is a snippet of the data from table_1:
user_id
day_ts
value_x
event
50
4/2/21 07:37
25
0
50
4/2/21 07:42
45
0
50
4/2/21 09:14
67
1
50
4/5/21 10:09
8
0
50
4/5/21 10:24
75
0
50
4/8/21 11:08
34
0
50
4/15/21 13:09
32
1
50
4/16/21 14:23
12
0
50
4/29/21 14:34
90
0
55
4/4/21 15:31
12
0
55
4/5/21 15:23
34
0
55
4/17/21 18:58
32
1
55
4/17/21 19:00
66
1
55
4/18/21 19:57
54
0
55
4/23/21 20:02
34
0
55
4/29/21 20:39
57
0
55
4/30/21 21:46
43
0
Technical details:
PostgreSQL, supported by EDB, version = 14.1
pgAdmin4, version 5.7
Thanks for the help!
"The query currently first creates daily aggregate values"
I don't see any aggregate function in your first query, so that the GROUP BY clause is useless.
select
user_id, value_x, date_part('day', day_ts) as daily
from table_1
group by date_part('day', day_ts), user_id, value_x
could be simplified as
select
user_id, value_x, date_part('day', day_ts) as daily
from table_1
which in turn provides no real added value, so this first query could be removed and the second query would become :
select user_id
, date_part('day', day_ts) as daily
, sum(value_x) as sum_daily_value_x
from table_1
group by user_id, date_part('day', day_ts)
The order by user_id clause can also be removed at this step.
Now if you want to calculate the average value of the sum_daily_value_x in the period of 7 days after the event (I'm referring to the avg() function in your top query), you can use avg() as a window function that you can restrict to the period of 7 days after the event :
select f.user_id
, avg(f.sum_daily_value_x) over (order by f.daily range between current row and '7 days' following) as sum_next_day_values
from (
select user_id
, date_part('day', day_ts) as daily
, sum(value_x) as sum_daily_value_x
from table_1
group by user_id, date_part('day', day_ts)
) AS f
group by f.user_id
The partition by f.user_id clause in the window function is useless because the rows have already been grouped by f.user_id before the window function is applied.
You can replace the avg() window function by any other one, for instance sum() which could better fit with the alias sum_next_day_values
I have a postgres query like this
select application.status as status, count(*) as "current_month" from application
where to_char(application.created, 'mon') = to_char('now'::timestamp - '1 month'::interval, 'mon')
and date_part('year',application.created) = date_part('year', CURRENT_DATE)
and application.job_status != 'expired'
group by application.status
it returns the table below that has the number of applications grouped by status for the current month. However I want to subtract a total count of a seperate but related query from the internal review number only. I want to count the number of rows with type = abc within the same table and for the same date range and then subtract that amount from the internal review number (Type is a seperate field). Current_month_desired is how it should look.
status
current_month
current_month_desired
fail
22
22
internal_review
95
22
pass
146
146
UNTESTED: but maybe...
The intent here is to use an analytic and case expression to conditionally sum. This way, the subtraction is not needed in the first place as you are only "counting" the values needed.
SELECT application.status as status
, sum(case when type = 'abc'
and application.status ='internal_review' then 0
else 1 end) over (partition by application.status)) as
"current_month"
FROM application
WHERE to_char(application.created, 'mon') = to_char('now'::timestamp - '1 month'::interval, 'mon')
and date_part('year',application.created) = date_part('year', CURRENT_DATE)
and application.job_status != 'expired'
GROUP BY application.status
I need to find the number of users that were invoiced for an amount greater than 0 in the previous month and were not invoiced in the current month. This calcualtion is to be done for 12 months in a single query. Output should be as below.
Month Count
01/07/2019 50
01/08/2019 34
01/09/2019 23
01/10/2019 98
01/11/2019 10
01/12/2019 5
01/01/2020 32
01/02/2020 65
01/03/2020 23
01/04/2020 12
01/05/2020 64
01/06/2020 54
01/07/2020 78
I am able to get the value only for one month. I want to get it for all months in a single query.
This is my current query:
SELECT COUNT(DISTINCT TWO_MONTHS_AGO.USER_ID), TWO_MONTHS_AGO.MONTH AS INVOICE_MONTH
FROM (
SELECT USER_ID, LAST_DAY(invoice_ct_dt)) AS MONTH
FROM table a AS ID
WHERE invoice_amt > 0
AND LAST_DAY(invoice_ct_dt)) = ADD_MONTHS(LAST_DAY(CURRENT_DATE - 1), - 2)
GROUP BY user_id
) AS TWO_MONTHS_AGO
LEFT JOIN (
SELECT user_id,LAST_DAY(invoice_ct_dt)) AS MONTH
FROM table a AS ID
AND LAST_DAY(invoice_ct_dt)) = ADD_MONTHS(LAST_DAY(CURRENT_DATE - 1), - 1)
GROUP BY USER_ID
) AS ONE_MONTH_AGO ON TWO_MONTHS_AGO.USER_ID = ONE_MONTH_AGO.USER_ID
WHERE ONE_MONTH_AGO.USER_ID IS NULL
GROUP BY INVOICE_MONTH;
Thank you in advance.
Lona
Probably lots of different approaches but the way I would do it is as follows:
Summarise data by user and month for the last 13 months (you need 12 months plus the previous month to that first month
Compare "this" month (that has data) to "next" month and select records where there is no "next" month data
Summarise this dataset by month and distinct userid
For example, assuming a table created as follows:
create table INVOICE_DATA (
USERID varchar(4),
INVOICE_DT date,
INVOICE_AMT NUMBER(10,2)
);
the following query should give you what you want - you may need to adjust it depending on whether you are including this month, or only up to the end of last month, in your calculation, etc.:
--Summarise data by user and month
WITH MONTH_SUMMARY AS
(
SELECT USERID
,TO_CHAR(INVOICE_DT,'YYYY-MM') "INVOICE_MONTH"
,TO_CHAR(ADD_MONTHS(INVOICE_DT,1),'YYYY-MM') "NEXT_MONTH"
,SUM(INVOICE_AMT) "MONTHLY_TOTAL"
FROM INVOICE_DATA
WHERE INVOICE_DT >= TRUNC(ADD_MONTHS(current_date(),-13),'MONTH') -- Last 13 months of data
GROUP BY 1,2,3
),
--Get data for users with invoices in this month but not the next month
USER_DATA AS
(
SELECT USERID, INVOICE_MONTH, MONTHLY_TOTAL
FROM MONTH_SUMMARY MS_THIS
WHERE NOT EXISTS
(
SELECT USERID
FROM MONTH_SUMMARY MS_NEXT
WHERE
MS_THIS.USERID = MS_NEXT.USERID AND
MS_THIS.NEXT_MONTH = MS_NEXT.INVOICE_MONTH
)
AND MS_THIS.INVOICE_MONTH < TO_CHAR(current_date(),'YYYY-MM') -- Don't include this month as obviously no next month to compare to
)
SELECT INVOICE_MONTH, COUNT(DISTINCT USERID) "USER_COUNT"
FROM USER_DATA
GROUP BY INVOICE_MONTH
ORDER BY INVOICE_MONTH
;
This is a follow-up to my earlier question, now that the requirements have changed again after the analysts clarified the requirements
I have a dataset like the below using the help I received:
I need to be able to identify row 2, where the TotalWeeks column has reached or exceeded 23 weeks, so I can return the correct ToDate value.
to get that dataset I am using a query like this:
Select
idcol
, FromDate
, ToDate
, NoOfDays
, Weeks
, Linked
, sum(Weeks) over(order by idcol desc) TotalWeeks
from
#tmpAbsences
where
idcol between 1 AND (
Select TOP 1 idcol from #tmpAbsences where Linked=0)
ORDER BY
ToDate DESC
But how could I alwauys identify the record where the TotalWeeks reaches the value I am checking for - either 23 weeks (and less than 28) or greater than or equal to 28 weeks?
thanks
I think you could use the Having clause
Something like
Having (sum(weeks) >= 23 and SUM(weeks) < 28) or sum(weeks) >= 28