I have a table db2admin.shdl_dtl in which there are two columns for the date-
startdate
enddate
from these two date columns I want to show months between two dates
i.e. startdate = '2015-01-05' and enddate = '2015-04-20' then output of the query should come like this-
Output- jan, feb, mar, apr
with cte (diffmonths,monthdiff) as
(select date(startdate ) as diffmonths,0 from sysibm.sysdummy1
union all
select date(diffmonths) + 1 month as diffmonths,month(diffmonths) from cte
where diffmonths<=(date(enddate)) )
select * from cte where MONTHDIFF >0
Related
I'm currently writing an application which shows the growth of the total number of events in my table over time, I currently have the following query to do this:
query = session.query(
count(Event.id).label('count'),
extract('year', Event.date).label('year'),
extract('month', Event.date).label('month')
).filter(
Event.date.isnot(None)
).group_by('year', 'month').all()
This results in the following output:
Count
Year
Month
100
2021
1
50
2021
2
75
2021
3
While this is okay on it's own, I want it to display the total number over time, so not just the number of events that month, so the desired outpout should be:
Count
Year
Month
100
2021
1
150
2021
2
225
2021
3
I read on various places I should use a window function using SqlAlchemy's over function, however I can't seem to wrap my head around it and every time I try using it I get the following error:
sqlalchemy.exc.ProgrammingError: (psycopg2.errors.GroupingError) column "event.id" must appear in the GROUP BY clause or be used in an aggregate function
LINE 1: SELECT count(event.id) OVER (PARTITION BY event.date ORDER...
^
[SQL: SELECT count(event.id) OVER (PARTITION BY event.date ORDER BY EXTRACT(year FROM event.date), EXTRACT(month FROM event.date)) AS count, EXTRACT(year FROM event.date) AS year, EXTRACT(month FROM event.date) AS month
FROM event
WHERE event.date IS NOT NULL GROUP BY year, month]
This is the query I used:
session.query(
count(Event.id).over(
order_by=(
extract('year', Event.date),
extract('month', Event.date)
),
partition_by=Event.date
).label('count'),
extract('year', Event.date).label('year'),
extract('month', Event.date).label('month')
).filter(
Event.date.isnot(None)
).group_by('year', 'month').all()
Could someone show me what I'm doing wrong? I've been searching for hours but can't figure out how to get the desired output as adding event.id in the group by would stop my rows from getting grouped by month and year
The final query I ended up using:
query = session.query(
extract('year', Event.date).label('year'),
extract('month', Event.date).label('month'),
func.sum(func.count(Event.id)).over(order_by=(
extract('year', Event.date),
extract('month', Event.date)
)).label('count'),
).filter(
Event.date.isnot(None)
).group_by('year', 'month')
I'm not 100% sure what you want, but I'm assuming you want the number of events up to that month for each month. You're going to first need to calculate the # of events per month and also sum them with the postgresql window function.
You can do that with in a single select statement:
SELECT extract(year FROM events.date) AS year
, extract(month FROM events.date) AS month
, SUM(COUNT(events.id)) OVER(ORDER BY extract(year FROM events.date), extract(month FROM events.date)) AS total_so_far
FROM events
GROUP BY 1,2
but it might be easier to think about if you split it into two:
SELECT year, month, SUM(events_count) OVER(ORDER BY year, month)
FROM (
SELECT extract(year FROM events.date) AS year
, extract(month FROM events.date) AS month
, COUNT(events.id) AS events_count
FROM events
GROUP BY 1,2
)
but not sure how to do that in SqlAlchemy
I currently have the following code in Microsoft SQL Server to get users that viewed on two days in a row.
WITH uservideoviewvideo (date, user_id) AS (
SELECT DISTINCT date, user_id
FROM clickstream_videos
WHERE event_name ='video_play'
and user_id IS NOT NULL
)
SELECT currentday.date AS date,
COUNT(currentday.user_id) AS users_view_videos,
COUNT(nextday.user_id) AS users_view_next_day
FROM userviewvideo currentday
LEFT JOIN userviewvideo nextday
ON currentday.user_id = nextday.user_id AND DATEADD(DAY, 1,
currentday.date) = nextday.date
GROUP BY currentday.date
I am trying to get the DATEADD function to work in PostgreSQL but I've been unable to figure out how to get this to work. Any suggestions?
I don't think PostgreSQL really has a DATEADD function. Instead, just do:
+ INTERVAL '1 day'
SQL Server:
Add 1 day to the current date November 21, 2012
SELECT DATEADD(day, 1, GETDATE()); # 2012-11-22 17:22:01.423
PostgreSQL:
Add 1 day to the current date November 21, 2012
SELECT CURRENT_DATE + INTERVAL '1 day'; # 2012-11-22 17:22:01
SELECT CURRENT_DATE + 1; # 2012-11-22 17:22:01
http://www.sqlines.com/postgresql/how-to/dateadd
EDIT:
It might be useful if you're using a dynamic length of time to create a string and then cast it as an interval like:
+ (col_days || ' days')::interval
You can use date + 1 to do the equivalent of dateadd(), but I do not think that your query does what you want to do.
You should use window functions, instead:
with plays as (
select distinct date, user_id
from clickstream_videos
where event_name = 'video_play'
and user_id is not null
), nextdaywatch as (
select date, user_id,
case
when lead(date) over (partition by user_id
order by date) = date + 1 then 1
else 0
end as user_view_next_day
from plays
)
select date,
count(*) as users_view_videos,
sum(user_view_next_day) as users_view_next_day
from nextdaywatch
group by date
order by date;
There is one table:
ID DATE
1 2017-09-16 20:12:48
2 2017-09-16 20:38:54
3 2017-09-16 23:58:01
4 2017-09-17 00:24:48
5 2017-09-17 00:26:42
..
The result I need is the last 7-days of data with hourly aggregated count of rows:
COUNT DATE
2 2017-09-16 21:00:00
0 2017-09-16 22:00:00
0 2017-09-16 23:00:00
1 2017-09-17 00:00:00
2 2017-09-17 01:00:00
..
I tried different stuff with EXTRACT, DISTINCT and also used the generate_series function (most stuff from similar stackoverflow questions)
This try was the best one currently:
SELECT
date_trunc('hour', demotime) as date,
COUNT(demotime) as count
FROM demo
GROUP BY date
How to generate hourly series for 7 days and fill-in the count of rows?
SQL DEMO
SELECT dd, count("demotime")
FROM generate_series
( current_date - interval '7 days'
, current_date
, '1 hour'::interval) dd
LEFT JOIN Table1
ON dd = date_trunc('hour', demotime)
GROUP BY dd;
To work from now and now - 7 days:
SELECT dd, count("demotime")
FROM generate_series
( date_trunc('hour', NOW()) - interval '7 days'
, date_trunc('hour', NOW())
, '1 hour'::interval) dd
LEFT JOIN Table1
ON dd = date_trunc('hour', demotime)
GROUP BY dd;
I would like to insert subquery a date based on it day. Plus, each date can only be used four times. Once it reached fourth times, the fifth value will use another date of same day. In other word, use date of Monday of next week. Example, Monday with 6 JUNE 2016 to Monday with 13 JUNE 2016 (you may check the calendar).
I have a query of getting a list of date based on presentationdatestart and presentationdateend from presentation table:
select a.presentationid,
a.presentationday,
to_char (a.presentationdatestart + delta, 'DD-MM-YYYY', 'NLS_CALENDAR=GREGORIAN') list_date
from presentation a,
(select level - 1 as delta
from dual
connect by level - 1 <= (select max (presentationdateend - presentationdatestart)
from presentation))
where a.presentationdatestart + delta <= a.presentationdateend
and a.presentationday = to_char(a.presentationdatestart + delta, 'fmDay')
order by a.presentationdatestart + delta,
a.presentationid; --IMPORTANT!!!--
For example,
presentationday presentationdatestart presentationdateend
Monday 01-05-2016 04-06-2016
Tuesday 01-05-2016 04-06-2016
Wednesday 01-05-2016 04-06-2016
Thursday 01-05-2016 04-06-2016
The query result will list all possible dates between 01-05-2016 until 04-06-2016:
Monday 02-05-2016
Tuesday 03-05-2016
Wednesday 04-05-2016
Thursday 05-05-2016
....
Monday 30-05-2016
Tuesday 31-05-2016
Wednesday 01-06-2016
Thursday 02-06-2016 (20 rows)
This is my INSERT query :
insert into CSP600_SCHEDULE (studentID,
studentName,
projectTitle,
supervisorID,
supervisorName,
examinerID,
examinerName,
exavailableID,
availableday,
availablestart,
availableend,
availabledate)
select '2013816591',
'mong',
'abc',
'1004',
'Sue',
'1002',
'hazlifah',
2,
'Monday', //BASED ON THIS DAY
'12:00:00',
'2:00:00',
to_char (a.presentationdatestart + delta, 'DD-MM-YYYY', 'NLS_CALENDAR=GREGORIAN') list_date //FOR AVAILABLEDATE
from presentation a,
(select level - 1 as delta
from dual
connect by level - 1 <= (select max (presentationdateend - presentationdatestart)
from presentation))
where a.presentationdatestart + delta <= a.presentationdateend
and a.presentationday = to_char(a.presentationdatestart + delta, 'fmDay')
order by a.presentationdatestart + delta,
a.presentationid;
This query successfully added 20 rows because all possible dates were 20 rows. I would like modify the query to be able to insert based on availableDay and each date can only be used four times for each different studentID.
Possible outcome in CSP600_SCHEDULE (I am removing unrelated columns to ease readability):
StudentID StudentName availableDay availableDate
2013 abc Monday 01-05-2016
2014 def Monday 01-05-2016
2015 ghi Monday 01-05-2016
2016 klm Monday 01-05-2016
2010 nop Tuesday 02-05-2016
2017 qrs Tuesday 02-05-2016
2018 tuv Tuesday 02-05-2016
2019 wxy Tuesday 02-05-2016
.....
2039 rrr Monday 09-05-2016
.....
You may check the calendar :)
I think what you're asking for is to list your students and then batch them up in groups of 4 - each batch is then allocated to a date. Is that right?
In which case something like this should work (I'm using a list of tables as the student names just so I don't need to insert any data into a custom table) :
WITH students AS
(SELECT table_name
FROM all_tables
WHERE rownum < 100
)
SELECT
table_name
,SYSDATE + (CEIL(rownum/4) -1)
FROM
students
;
I hope that helps you
...okay, following your comments, I think this might be a better solution :
WITH students AS
(SELECT table_name student_name
FROM all_tables
WHERE rownum < 100
)
, dates AS
(SELECT TRUNC(sysdate) appointment_date from dual UNION
SELECT TRUNC(sysdate+2) from dual UNION
SELECT TRUNC(sysdate+4) from dual UNION
SELECT TRUNC(sysdate+6) from dual UNION
SELECT TRUNC(sysdate+8) from dual UNION
SELECT TRUNC(sysdate+10) from dual UNION
SELECT TRUNC(sysdate+12) from dual UNION
SELECT TRUNC(sysdate+14) from dual
)
SELECT
s.student_name
,d.appointment_date
FROM
--get a list of students each with a sequential row number, ordered by student name
(SELECT
student_name
,ROW_NUMBER() OVER (ORDER BY student_name) rn
FROM students
) s
--get a list of available dates with a sequential row number, ordered by date
,(SELECT
appointment_date
,ROW_NUMBER() OVER (ORDER BY appointment_date) rn
FROM dates
) d
WHERE 1=1
--allocate the first four students to date rownumber1, next four students to date rownumber 2...
AND CEIL(s.rn/4) = d.rn
;
I've had a hunt around for something similar to this but can't find anything.
I have a query that provides the number of transactions that have occurred each day and need to group by year, month, week BUT of course some months span multiple week numbers, eg. Sept. & Oct. 2009.
Take for example week 39 last year (September & October). Thursday is the 1st October therefore 4 days of that week fall in Oct., therefore the volume of transactions for the last 3 days of Sept. should be added to the first week of October's totals? Clear?
For example:
VOLUME----TRANSACTION----YEAR----MONTH----WEEK
1264.1730----53----2009----September----37
2739.7200---109----2009----September----38
522.5500-----21----2009----October----39
1196.6450----51----2009----September----39
2827.9550---113----2009----October----40
2730.4050---110----2009----October----41
3763.7200---154----2009----October----42
3425.6250---137----2009----October----43
3551.8100---143----2009----November--44
2788.0150---113----2009----November--45
The problem is that the calendar is awkward, and there's not much you can do about it. As far as I can see, you have three choices:
Group by year and month. Display the week or weeks in the result but don't group by them.
Group by year and weeks. Display the month or months in the result but don't group by them.
Group by year, month, week, and accept that some of the groups contain less than one week's data. (i.e. what you have now)
From your description it seems like you want option 2:
SELECT year, MIN(month), week, SUM(transaction)
FROM Table1
GROUP BY year, week
Something like this would do:
-- For weeks starting Sunday and ending Saturday, the US default:
SET DATEFIRST 7
-- Alternatively, for weeks starting Saturday and ending Friday:
--SET DATEFIRST 6
SELECT
[Date]
, DATENAME(WEEKDAY,[Date]) AS [DayOfWeek]
, DATEADD(DAY,1-DATEPART(WEEKDAY,[Date]),[Date]) AS WeekStarting
, DATEADD(DAY,7-DATEPART(WEEKDAY,[Date]),[Date]) AS WeekEnding
FROM (
SELECT CONVERT(DATETIME,'20100124') UNION ALL
SELECT CONVERT(DATETIME,'20100125') UNION ALL
SELECT CONVERT(DATETIME,'20100126') UNION ALL
SELECT CONVERT(DATETIME,'20100127') UNION ALL
SELECT CONVERT(DATETIME,'20100128') UNION ALL
SELECT CONVERT(DATETIME,'20100129') UNION ALL
SELECT CONVERT(DATETIME,'20100130') UNION ALL
SELECT CONVERT(DATETIME,'20100131') UNION ALL
SELECT CONVERT(DATETIME,'20100201') UNION ALL
SELECT CONVERT(DATETIME,'20100202') UNION ALL
SELECT CONVERT(DATETIME,'20100203') UNION ALL
SELECT CONVERT(DATETIME,'20100204') UNION ALL
SELECT CONVERT(DATETIME,'20100205') UNION ALL
SELECT CONVERT(DATETIME,'20100206')
) a ([Date])
Then, convert your week start or end date to a month:
SELECT *
, WeekStartingMonthStart = DATEADD(DAY,1-DAY(WeekStarting),WeekStarting)
, WeekStartingMonthEnd = DATEADD(DAY,-1,DATEADD(MONTH,1,DATEADD(DAY,1-DAY(WeekStarting),WeekStarting)))
, WeekEndingMonthStart = DATEADD(DAY,1-DAY(WeekEnding),WeekEnding)
, WeekEndingMonthEnd = DATEADD(DAY,-1,DATEADD(MONTH,1,DATEADD(DAY,1-DAY(WeekEnding),WeekEnding)))
FROM (
SELECT
[Date]
, DATENAME(WEEKDAY,[Date]) AS [DayOfWeek]
, DATEADD(DAY,1-DATEPART(WEEKDAY,[Date]),[Date]) AS WeekStarting
, DATEADD(DAY,7-DATEPART(WEEKDAY,[Date]),[Date]) AS WeekEnding
FROM (
SELECT CONVERT(DATETIME,'20100124') UNION ALL
SELECT CONVERT(DATETIME,'20100125') UNION ALL
SELECT CONVERT(DATETIME,'20100126') UNION ALL
SELECT CONVERT(DATETIME,'20100127') UNION ALL
SELECT CONVERT(DATETIME,'20100128') UNION ALL
SELECT CONVERT(DATETIME,'20100129') UNION ALL
SELECT CONVERT(DATETIME,'20100130') UNION ALL
SELECT CONVERT(DATETIME,'20100131') UNION ALL
SELECT CONVERT(DATETIME,'20100201') UNION ALL
SELECT CONVERT(DATETIME,'20100202') UNION ALL
SELECT CONVERT(DATETIME,'20100203') UNION ALL
SELECT CONVERT(DATETIME,'20100204') UNION ALL
SELECT CONVERT(DATETIME,'20100205') UNION ALL
SELECT CONVERT(DATETIME,'20100206')
) a ([Date])
) a