I have a table that lists all employees and their respective start and end dates
I want to be able to count the number of active employees in each month. Is there a way to do this via a single query (eg groupBy) rather than generating multiple queries for each month?
=================================
Employee ID | StartDt | EndDt
123 | 01 Feb 2022 |
234 | 01 jan 2022 | 28 Feb 2022
456 | 01 dec 2021 | 28 Feb 2022
As an example, the table above should return:
Dec 2021: 1
Jan 2022: 2
Feb 2022: 3
Mar 2022: 1
Apr 2022: 1
You can generate a calendar and join to that:
WITH calendar (month) AS (
SELECT ADD_MONTHS(min_startdt, LEVEL - 1)
FROM (
SELECT MIN(startdt) AS min_startdt,
MAX(COALESCE(enddt, SYSDATE)) AS max_enddt
FROM employees
)
CONNECT BY LEVEL - 1 <= MONTHS_BETWEEN(max_enddt, min_startdt)
)
SELECT c.month,
COUNT(e.employee_id)
FROM calendar c
LEFT OUTER JOIN employees e
ON (e.startdt <= c.month AND (c.month <= e.enddt OR e.enddt IS NULL))
GROUP BY
c.month
Which, for the sample data:
CREATE TABLE employees (Employee_ID, StartDt, EndDt ) AS
SELECT 123, DATE '2022-02-01', NULL FROM DUAL UNION ALL
SELECT 234, DATE '2022-01-01', DATE '2022-02-28' FROM DUAL UNION ALL
SELECT 456, DATE '2021-12-01', DATE '2022-02-28' FROM DUAL;
Outputs:
MONTH
COUNT(E.EMPLOYEE_ID)
2021-12-01 00:00:00
1
2022-01-01 00:00:00
2
2022-02-01 00:00:00
3
2022-03-01 00:00:00
1
2022-04-01 00:00:00
1
db<>fiddle here
I need to adapt a graph from the current BI implementation to an SQL one. This graph reflects the amount of requests received and each one of these requests have 3 fields that are relevant for this query: the id, created date and the end date.
The graph looks like this https://i.stack.imgur.com/NRIjr.png:
+----+--------------+-------------+
| ID | CREATE_DATE | END_DATE |
+----+--------------+-------------+
| | | |
| 1 | 2022-01-01 | 2022-02-10 |
| | | |
| 2 | 2022-01-03 | 2022-03-01 |
| | | |
| 3 | 2022-02-01 | 2022-04-01 |
| | | |
| 4 | 2022-03-01 | null |
+----+--------------+-------------+
So for this particular example we'd have something like this:
January: active: 2 (requests 1 and 2), finished: 0;
February: active 2 (requests 2, 3), finished 1 (request 1);
March: active 2 (requests 3, 4) finished 1 (request 2)
So for each month I want the active requests for that particular month (those that their ended date goes after that particular month or is null) and the requests that finished during that month (this one might be split to another query, of course) I tried this query, but of course, it doesn't take into account the requests that ended in a particular month, and only gives me the cumulative sum
Edit: I forgot to mention that one of the requirements is that the beggining and end date of the graph might be set by the user. So maybe I want to see the months from April-2022 to April-2020 and see the 2 year behaviour!
WITH cte AS ( SELECT
date_trunc('month',
r.date_init) AS mon,
count(r.id) AS mon_sum
FROM
"FOLLOWUP"."CAT_REQUEST" r
GROUP BY
1 ) SELECT
to_char(mon,
'YYYY-mm') AS mon_text,
COALESCE(sum(c.mon_sum)
OVER (ORDER BY mon),
0) AS running_sum
FROM
generate_series('2022-01-01', '2023-12-25',
interval '1 month') mon
LEFT JOIN
cte c USING (mon)
ORDER BY
mon
I wrote query for you using some different business logic. But, result is will be same result which you needed. Sample query:
with month_list as (
select 1 as id, 'Yanuary' as mname union all
select 2 as id, 'Febriary' as mname union all
select 3 as id, 'Marth' as mname union all
select 4 as id, 'April' as mname union all
select 5 as id, 'May' as mname union all
select 6 as id, 'June' as mname union all
select 7 as id, 'Jule' as mname union all
select 8 as id, 'August' as mname union all
select 9 as id, 'September' as mname union all
select 10 as id, 'October' as mname union all
select 11 as id, 'November' as mname union all
select 12 as id, 'December' as mname
),
test_table as (
select
id,
create_date,
end_date,
extract(month from create_date) as month1,
extract(month from end_date) as month2
from
your_table
)
select
t1.mname,
count(*) as "actived"
from
month_list t1
inner join
test_table t2 on (t1.id >= t2.month1) and (t1.id < t2.month2)
group by
t1.id, t1.mname
order by
t1.id
/* --- Result:
mname actived
--------------------
Yanuary 2
Febriary 2
Marth 1
*/
PostgreSQL has many date & time functions and types.
I write some samples for you:
For example, in my samples function now() our chosen date.
-- get previos 12 month from date (return timestampt)
select now() - '12 month'::interval as newdate
-- Return:
2021-04-03 18:22:48.344 +0400
-- if you need only date, you can cast this to date
select (now() - '12 month'::interval)::date as newdate
-- Return:
2021-04-03
-- generate data from previous 12 month to selected date increase by month:
SELECT t1.datelist::date
from generate_series
(
now()-'12 month'::interval,
now(),
'1 month'
)
AS t1(datelist)
-- Return:
2021-04-03
2021-05-03
2021-06-03
2021-07-03
2021-08-03
2021-09-03
2021-10-03
2021-11-03
2021-12-03
2022-01-03
2022-02-03
2022-03-03
2022-04-03
-- generate data from previous 12 month to selected date increase by month with extracting month names and year:
-- this sample may be as you needed.
SELECT
extract(year from t1.datelist) as "year",
TO_CHAR(t1.datelist, 'Month') as "month",
trim(TO_CHAR(t1.datelist, 'Month')) || '-' || trim(to_char(t1.datelist, 'yyyy')) as "formatted_date"
from generate_series
(
now()-'12 month'::interval,
now(),
'1 month'
)
AS t1(datelist)
-- Return:
year month formatted_date
------------------------------------
2021 April April-2021
2021 May May-2021
2021 June June-2021
2021 July July-2021
2021 August August-2021
2021 September September-2021
2021 October October-2021
2021 November November-2021
2021 December December-2021
2022 January January-2022
2022 February February-2022
2022 March March-2022
2022 April April-2022
I did try to use this query
UPDATE people
SET BIRTHDATE = replace (BIRTHDATE, '%:00 2%' ,'%:00 2000')
WHERE BIRTHDATE IN (select birthdate from people)
current data
BIRTHDATE
Mon Jan 27 00:00:00 **2020**
Mon Jan 27 00:00:00 **2130**
Mon Jan 27 00:00:00 **1920**
If birthdate is a string, and you want to replace the 4 rightmost digits that start with '2' with '2000', a solution is to use regexp_replace():
update crm_customer_data
set birthdate = regexp_replace(birthdate, '2\d{3}$' ,'2000')
Regexp detail:
2 the number '2'
\d{3} 3 digits
$ end of the string
Without sample data it is unclear what is the purpose of the in condition with the subquery, so I left it apart for now.
Demo on DB Fiddle:
select regexp_replace('Mon Jan 27 00:00:00 2020', '2\d{3}$', '2000') from dual
| REGEXP_REPLACE('MONJAN2700:00:002020','2\D{3}$','2000') |
| :------------------------------------------------------ |
| Mon Jan 27 00:00:00 2000 |
Use simple string functions:
Oracle Setup:
CREATE TABLE crm_customer_data ( birthdate ) AS
SELECT 'Mon Jan 27 00:00:00 2020' FROM DUAL UNION ALL
SELECT 'Mon Jan 27 00:00:00 2130' FROM DUAL UNION ALL
SELECT 'Mon Jan 27 00:00:00 1920' FROM DUAL UNION ALL
SELECT 'Mon Jan 27 00:00:00 2020' FROM DUAL;
Update:
UPDATE crm_customer_data
SET BIRTHDATE = SUBSTR( BIRTHDATE, 1, LENGTH( BIRTHDATE ) - 4 ) || '2000'
-- WHERE BIRTHDATE IN (select birthdate from people)
-- AND BIRTHDATE LIKE '%2___'
Output:
SELECT * FROM crm_customer_data
| BIRTHDATE |
| :----------------------- |
| Mon Jan 27 00:00:00 2000 |
| Mon Jan 27 00:00:00 2000 |
| Mon Jan 27 00:00:00 2000 |
| Mon Jan 27 00:00:00 2000 |
db<>fiddle here
I wrote this SQL statement to calculate the days for each month
(select count(*) DAYs FROM
(
select trunc(ADD_MONTHS(sysdate,-1),'MM') + level -1 Dates from dual connect by
level <= ADD_MONTHS(trunc(sysdate,'MM'),1)-1 - trunc(sysdate,'MM')+1
) Where To_char(dates,'DY') NOT IN ('SA','SO'))
At the moment this statement ignores Saturdays and Sundays and it calculates the days from the month before the sysdate (June).
June has 22 days without weekends but sadly my statement says it has 23. I found out it includes the 1st July, which is wrong.
Do you know how I can tell my little statement it only calculates the days from the month I want to get not including days from another month?
Doing this sort of thing is always going to look not pretty... here's one way, which does it for the entire current year. You can restrict to a single month by adding an additional statement to the where clause:
select to_char(trunc(sysdate, 'y') + level - 1, 'fmMON') as month, count(*)
from dual
where to_char(trunc(sysdate, 'y') + level - 1, 'fmDY', 'nls_date_language=english') not in ('SAT','SUN')
connect by level <= trunc(add_months(sysdate, 12), 'y') - trunc(sysdate, 'y')
group by to_char(trunc(sysdate, 'y') + level - 1, 'fmMON')
As I said, not pretty.
Note a couple of things:
Use of the fm format model modifier to remove leading spaces
Explicit use of nls_date_language to ensure it'll work in all environments
I've added 12 months to the current date and then truncated it to the first of January to get the first day of the new year for simplicity
If you want to do this by month it might be worth looking at the LAST_DAY() function
The same statement (using LAST_DAY()) for the previous month only would be:
select count(*)
from dual
where to_char(trunc(sysdate, 'y') + level - 1, 'fmDY', 'nls_date_language=english') not in ('SAT','SUN')
connect by level <= last_day(add_months(trunc(sysdate, 'mm'), -1)) - add_months(trunc(sysdate, 'mm'), -1) + 1
Firstly, your inner query (select trunc(ADD_MONTHS(sysdate,-1),'MM') + level -1 Dates from dual connect by level <= ADD_MONTHS(trunc(sysdate,'MM'),1)-1 - trunc(sysdate,'MM')+1) returns the days of the month plus one extra day from the next month.
Secondly, a simpler query could use the LAST_DAY function which gets the last day of the month.
Finally, use the 'D' date format to get the day of the week as a number.
SELECT COUNT(*) FROM (
SELECT TO_CHAR(TRUNC(SYSDATE,'MM') + ROWNUM - 1, 'D') d
FROM dual CONNECT BY LEVEL <= TO_NUMBER(TO_CHAR(LAST_DAY(SYSDATE),'DD'))
) WHERE d BETWEEN 1 AND 5;
Without having to generate all days of the month and then count them:
SQL Fiddle
Oracle 11g R2 Schema Setup:
CREATE FUNCTION WORK_DAYS_IN_MONTH(
dt DATE
) RETURN NUMBER DETERMINISTIC
AS
first_day DATE := TRUNC( dt, 'MM' );
remainder NUMBER := LAST_DAY( dt ) - ( first_day + INTERVAL '27' DAY );
BEGIN
RETURN 20 + CASE first_day - TRUNC( first_day, 'IW' )
WHEN 0 THEN remainder -- Monday
WHEN 1 THEN remainder -- Tuesday
WHEN 2 THEN remainder -- Wednesday
WHEN 3 THEN LEAST( remainder, 2 ) -- Thursday
WHEN 4 THEN LEAST( remainder, 1 ) -- Friday
WHEN 5 THEN GREATEST( remainder-2, 0 ) -- Saturday
ELSE GREATEST( remainder-1, 0 ) -- Sunday
END;
END;
//
Query 1:
SELECT ADD_MONTHS( DATE '2014-12-01', LEVEL ) AS "Month",
WORK_DAYS_IN_MONTH( ADD_MONTHS( DATE '2014-12-01', LEVEL ) ) AS "# Work Days"
FROM DUAL
CONNECT BY LEVEL <= 12
Results:
| Month | # Work Days |
|-----------------------------|-------------|
| January, 01 2015 00:00:00 | 22 |
| February, 01 2015 00:00:00 | 20 |
| March, 01 2015 00:00:00 | 22 |
| April, 01 2015 00:00:00 | 22 |
| May, 01 2015 00:00:00 | 21 |
| June, 01 2015 00:00:00 | 22 |
| July, 01 2015 00:00:00 | 23 |
| August, 01 2015 00:00:00 | 21 |
| September, 01 2015 00:00:00 | 22 |
| October, 01 2015 00:00:00 | 22 |
| November, 01 2015 00:00:00 | 21 |
| December, 01 2015 00:00:00 | 23 |
I need to get the difference between two dates say if the difference is 84 days, I should probably have output as 2 months and 14 days, the code I have just gives the totals. Here is the code
SELECT Months_between(To_date('20120325', 'YYYYMMDD'),
To_date('20120101', 'YYYYMMDD'))
num_months,
( To_date('20120325', 'YYYYMMDD') - To_date('20120101', 'YYYYMMDD') )
diff_in_days
FROM dual;
Output is:
NUM_MONTHS DIFF_IN_DAYS
2.774193548 84
I need for example the output for this query to be either 2 months and 14 days at worst, otherwise I won't mind if I can have the exact days after the months figure because those days are not really 14 because all months do not have 30 days.
select
dt1, dt2,
trunc( months_between(dt2,dt1) ) mths,
dt2 - add_months( dt1, trunc(months_between(dt2,dt1)) ) days
from
(
select date '2012-01-01' dt1, date '2012-03-25' dt2 from dual union all
select date '2012-01-01' dt1, date '2013-01-01' dt2 from dual union all
select date '2012-01-01' dt1, date '2012-01-01' dt2 from dual union all
select date '2012-02-28' dt1, date '2012-03-01' dt2 from dual union all
select date '2013-02-28' dt1, date '2013-03-01' dt2 from dual union all
select date '2013-02-28' dt1, date '2013-04-01' dt2 from dual union all
select trunc(sysdate-1) dt1, sysdate from dual
) sample_data
Results:
| DT1 | DT2 | MTHS | DAYS |
----------------------------------------------------------------------------
| January, 01 2012 00:00:00 | March, 25 2012 00:00:00 | 2 | 24 |
| January, 01 2012 00:00:00 | January, 01 2013 00:00:00 | 12 | 0 |
| January, 01 2012 00:00:00 | January, 01 2012 00:00:00 | 0 | 0 |
| February, 28 2012 00:00:00 | March, 01 2012 00:00:00 | 0 | 2 |
| February, 28 2013 00:00:00 | March, 01 2013 00:00:00 | 0 | 1 |
| February, 28 2013 00:00:00 | April, 01 2013 00:00:00 | 1 | 1 |
| August, 14 2013 00:00:00 | August, 15 2013 05:47:26 | 0 | 1.241273 |
Link to test: SQLFiddle
Updated for correctness. Originally answered by #jen.
with DATES as (
select TO_DATE('20120101', 'YYYYMMDD') as Date1,
TO_DATE('20120325', 'YYYYMMDD') as Date2
from DUAL union all
select TO_DATE('20120101', 'YYYYMMDD') as Date1,
TO_DATE('20130101', 'YYYYMMDD') as Date2
from DUAL union all
select TO_DATE('20120101', 'YYYYMMDD') as Date1,
TO_DATE('20120101', 'YYYYMMDD') as Date2
from DUAL union all
select TO_DATE('20130228', 'YYYYMMDD') as Date1,
TO_DATE('20130301', 'YYYYMMDD') as Date2
from DUAL union all
select TO_DATE('20130228', 'YYYYMMDD') as Date1,
TO_DATE('20130401', 'YYYYMMDD') as Date2
from DUAL
), MONTHS_BTW as (
select Date1, Date2,
MONTHS_BETWEEN(Date2, Date1) as NumOfMonths
from DATES
)
select TO_CHAR(Date1, 'MON DD YYYY') as Date_1,
TO_CHAR(Date2, 'MON DD YYYY') as Date_2,
NumOfMonths as Num_Of_Months,
TRUNC(NumOfMonths) as "Month(s)",
ADD_MONTHS(Date2, - TRUNC(NumOfMonths)) - Date1 as "Day(s)"
from MONTHS_BTW;
SQLFiddle Demo :
+--------------+--------------+-----------------+-----------+--------+
| DATE_1 | DATE_2 | NUM_OF_MONTHS | MONTH(S) | DAY(S) |
+--------------+--------------+-----------------+-----------+--------+
| JAN 01 2012 | MAR 25 2012 | 2.774193548387 | 2 | 24 |
| JAN 01 2012 | JAN 01 2013 | 12 | 12 | 0 |
| JAN 01 2012 | JAN 01 2012 | 0 | 0 | 0 |
| FEB 28 2013 | MAR 01 2013 | 0.129032258065 | 0 | 1 |
| FEB 28 2013 | APR 01 2013 | 1.129032258065 | 1 | 1 |
+--------------+--------------+-----------------+-----------+--------+
Notice, how for the last two dates, Oracle reports the decimal part of months (which gives days) incorrectly. 0.1290 corresponds to exactly 4 days with Oracle considering 31 days in a month (for both March and April).
I think that your question is not defined well enough, for the following reason.
Answers relying on months_between have to deal with the following issue: that the function reports exactly one month between 2013-02-28 and 2013-03-31, and between 2013-01-28 and 2013-02-28, and between 2013-01-31 and 2013-02-28 (I suspect that some answerers have not used these functions in practice, or are now going to have to review some production code!)
This is documented behaviour, in which dates that are both the last in their respective months or which fall on the same day of the month are judged to be an integer number of months apart.
So, you get the same result of "1" when comparing 2013-02-28 with 2013-01-28 or with 2013-01-31, but comparing it with 2013-01-29 or 2013-01-30 gives 0.967741935484 and 0.935483870968 respectively -- so as one date approaches the other the difference reported by this function can increase.
If this is not an acceptable situation then you'll have to write a more complex function, or just rely on a calculation that assumes 30 (for example) days per month. In the latter case, how will you deal with 2013-02-28 and 2013-03-31?
is this what you've ment ?
select trunc(months_between(To_date('20120325', 'YYYYMMDD'),to_date('20120101','YYYYMMDD'))) months,
round(To_date('20120325', 'YYYYMMDD')-add_months(to_date('20120101','YYYYMMDD'),
trunc(months_between(To_date('20120325', 'YYYYMMDD'),to_date('20120101','YYYYMMDD'))))) days
from dual;
Here I'm just doing the difference between today, and a CREATED_DATE DATE field in a table, which obviously is a date in the past:
SELECT
((FLOOR(ABS(MONTHS_BETWEEN(CREATED_DATE, SYSDATE))) / 12) * 12) || ' months, ' AS MONTHS,
-- we take total days - years(as days) - months(as days) to get remaining days
FLOOR((SYSDATE - CREATED_DATE) - -- total days
(FLOOR((SYSDATE - CREATED_DATE)/365)*12)*(365/12) - -- years, as days
-- this is total months - years (as months), to get number of months,
-- then multiplied by 30.416667 to get months as days (and remove it from total days)
FLOOR(((SYSDATE - CREATED_DATE)/365)*12 - (FLOOR((SYSDATE - CREATED_DATE)/365)*12)) * (365/12))
|| ' days ' AS DAYS
FROM MyTable
I use (365/12), or 30.416667, as my conversion factor because I'm using total days and removing years and months (as days) to get the remainder number of days. It was good enough for my purposes, anyway.
The solution I post will consider a month with 30 days
select CONCAT (CONCAT (num_months,' MONTHS '), CONCAT ((days-(num_months)*30),' DAYS '))
from (
SELECT floor(Months_between(To_date('20120325', 'YYYYMMDD'),
To_date('20120101', 'YYYYMMDD')))
num_months,
( To_date('20120325', 'YYYYMMDD') - To_date('20120101', 'YYYYMMDD') )
days
FROM dual);
Find out Year - Month- Day between two Days in Orale Sql
select
trunc(trunc(months_between(To_date('20120101', 'YYYYMMDD'),to_date('19910228','YYYYMMDD')))/12) years ,
trunc(months_between(To_date('20120101', 'YYYYMMDD'),to_date('19910228','YYYYMMDD')))
-
(trunc(trunc(months_between(To_date('20120101', 'YYYYMMDD'),to_date('19910228','YYYYMMDD')))/12))*12
months,
round(To_date('20120101', 'YYYYMMDD')-add_months(to_date('19910228','YYYYMMDD'),
trunc(months_between(To_date('20120101', 'YYYYMMDD'),to_date('19910228','YYYYMMDD'))))) days
from dual;
SELECT (MONTHS_BETWEEN(date2,date1) + (datediff(day,date2,date1))/30) as num_months,
datediff(day,date2,date1) as diff_in_days FROM dual;
// You should replace date2 with TO_DATE('2012/03/25', 'YYYY/MM/DD')
// You should replace date1 with TO_DATE('2012/01/01', 'YYYY/MM/DD')
// To get you results
See the query below (assumed #dt1 >= #dt2);
Declare #dt1 datetime = '2013-7-3'
Declare #dt2 datetime = '2013-5-2'
select abs(DATEDIFF(DD, #dt2, #dt1)) Days,
case when #dt1 >= #dt2
then case when DAY(#dt2)<=DAY(#dt1)
then Convert(varchar, DATEDIFF(MONTH, #dt2, #dt1)) + CONVERT(varchar, ' Month(s) ') + Convert(varchar, DAY(#dt1)-DAY(#dt2)) + CONVERT(varchar, 'Day(s).')
else Convert(varchar, DATEDIFF(MONTH, #dt2, #dt1)-1) + CONVERT(varchar, ' Month(s) ') + convert(varchar, abs(DATEDIFF(DD, #dt1, DateAdd(Month, -1, #dt1))) - (DAY(#dt2)-DAY(#dt1))) + CONVERT(varchar, 'Day(s).')
end
else 'See asumption: #dt1 must be >= #dt2'
end In_Months_Days
Returns:
Days | In_Months_Days
62 | 2 Month(s) 1Day(s).