Stuck on the problem below.
Current data: table1 |emp_id | date | day_one |week_num | -------------------------------------- | 100|2021-01-01| TRUE| 1| | 100|2021-01-02| NULL| NULL| | 100|2021-01-03| NULL| NULL| | 100|2021-01-04| NULL| NULL| | 100|2021-01-05| NULL| NULL| | 100|2021-01-06| NULL| NULL| | 100|2021-01-07| NULL| NULL| | 100|2021-01-08| NULL| NULL| | 100|2021-01-09| NULL| NULL| | 100|2021-01-10| NULL| NULL| | 100|2021-01-11| NULL| NULL| | 100|2021-01-12| NULL| NULL| | 100|2021-01-13| NULL| NULL| | 100|2021-01-14| NULL| NULL| --------------------------------------
Desired output:
|emp_id | dates | day_one |week_num | -------------------------------------- | 100|2021-01-01| TRUE| 1| | 100|2021-01-02| NULL| 1| | 100|2021-01-03| NULL| 1| | 100|2021-01-04| NULL| 1| | 100|2021-01-05| NULL| 1| | 100|2021-01-06| NULL| 1| | 100|2021-01-07| NULL| 1| | 100|2021-01-08| NULL| 2| | 100|2021-01-09| NULL| 2| | 100|2021-01-10| NULL| 2| | 100|2021-01-11| NULL| 2| | 100|2021-01-12| NULL| 2| | 100|2021-01-13| NULL| 2| | 100|2021-01-14| NULL| 2| --------------------------------------
The data has many employees across thousands of dates so it needs be done in a way where weeks are added based off the day_one column. I have used a lag/lead but if an employee has an 8 week cycle it becomes very inefficient. The code below gives the week_num =1, repeating gives 2 etc.
with t1 as (
select
*
,
LAG(week_num) OVER(PARTITION BY emp_id ORDER BY emp_id, dates) as second_day,
LAG(week_num, 2) OVER(PARTITION BY emp_id ORDER BY emp_id, dates) as third_day,
LAG(week_num, 3) OVER(PARTITION BY emp_id ORDER BY emp_id, dates) as forth_day,
LAG(week_num, 4) OVER(PARTITION BY emp_id ORDER BY emp_id, dates) as fifth_day,
LAG(week_num, 5) OVER(PARTITION BY emp_id ORDER BY emp_id, dates) as sixth_day,
LAG(week_num, 6) OVER(PARTITION BY emp_id ORDER BY emp_id, dates) as seventh_day
from table1
)
select
emp_id,
dates,
day_one,
case when week_num = 1 then 1
when second_day = 1 then 1
when third_day = 1 then 1
when forth_day = 1 then 1
when fifth_day = 1 then 1
when sixth_day = 1 then 1
when seventh_day = 1 then 1
else NULL
end as week_num
from table1
order by emp_id, dates
And level 2 to the problem. Current data:
|emp_id | dates | day_one |week_num | -------------------------------------- | 100|2021-01-01| TRUE| 1| | 100|2021-01-02| NULL| NULL| | 100|2021-01-03| NULL| NULL| | 100|2021-01-04| NULL| NULL| | 100|2021-01-05| NULL| NULL| | 100|2021-01-06| NULL| NULL| | 100|2021-01-07| NULL| NULL| | 100|2021-01-08| NULL| NULL| | 100|2021-01-09| NULL| NULL| | 100|2021-01-10| NULL| NULL| | 100|2021-01-11| NULL| NULL| | 100|2021-01-12| NULL| NULL| | 100|2021-01-13| NULL| NULL| | 100|2021-01-14| NULL| NULL| | 100|2021-01-15| NULL| NULL| | 100|2021-01-16| NULL| NULL| | 100|2021-01-17| NULL| NULL| | 100|2021-01-18| NULL| NULL| | 100|2021-01-19| NULL| NULL| | 100|2021-01-20| NULL| NULL| | 100|2021-01-21| NULL| NULL| | 100|2021-01-22| NULL| NULL| | 100|2021-01-23| NULL| NULL| | 100|2021-01-24| NULL| NULL| | 100|2021-01-25| NULL| NULL| | 100|2021-01-26| NULL| NULL| | 100|2021-01-27| NULL| NULL| | 100|2021-01-28| NULL| NULL| --------------------------------------
Desired output (repeating cycles):
|emp_id | dates | day_one |week_num | -------------------------------------- | 100|2021-01-01| TRUE| 1| | 100|2021-01-02| NULL| 1| | 100|2021-01-03| NULL| 1| | 100|2021-01-04| NULL| 1| | 100|2021-01-05| NULL| 1| | 100|2021-01-06| NULL| 1| | 100|2021-01-07| NULL| 1| | 100|2021-01-08| NULL| 2| | 100|2021-01-09| NULL| 2| | 100|2021-01-10| NULL| 2| | 100|2021-01-11| NULL| 2| | 100|2021-01-12| NULL| 2| | 100|2021-01-13| NULL| 2| | 100|2021-01-14| NULL| 2| | 100|2021-01-15| NULL| 1| | 100|2021-01-16| NULL| 1| | 100|2021-01-17| NULL| 1| | 100|2021-01-18| NULL| 1| | 100|2021-01-19| NULL| 1| | 100|2021-01-20| NULL| 1| | 100|2021-01-21| NULL| 1| | 100|2021-01-22| NULL| 2| | 100|2021-01-23| NULL| 2| | 100|2021-01-24| NULL| 2| | 100|2021-01-25| NULL| 2| | 100|2021-01-26| NULL| 2| | 100|2021-01-27| NULL| 2| | 100|2021-01-28| NULL| 2| --------------------------------------
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Answer
-- PLEASE PROVIDE SET UP SCRIPT FOR SAMPLE DATA IN FUTURE POSTS
CREATE TABLE #table1
(
emp_id INT
,dates DATE
,day_one VARCHAR(9)
,week_num_expected INT
);
INSERT INTO #table1(emp_id,dates,day_one,week_num_expected) VALUES
(100,'2021-01-01','TRUE',1),(100,'2021-01-02',NULL,1),(100,'2021-01-03',NULL,1),(100,'2021-01-04',NULL,1)
,(100,'2021-01-05',NULL,1),(100,'2021-01-06',NULL,1),(100,'2021-01-07',NULL,1),(100,'2021-01-08',NULL,2)
,(100,'2021-01-09',NULL,2),(100,'2021-01-10',NULL,2),(100,'2021-01-11',NULL,2),(100,'2021-01-12',NULL,2)
,(100,'2021-01-13',NULL,2),(100,'2021-01-14',NULL,2),(100,'2021-01-15',NULL,1),(100,'2021-01-16',NULL,1)
,(100,'2021-01-17',NULL,1),(100,'2021-01-18',NULL,1),(100,'2021-01-19',NULL,1),(100,'2021-01-20',NULL,1)
,(100,'2021-01-21',NULL,1),(100,'2021-01-22',NULL,2),(100,'2021-01-23',NULL,2),(100,'2021-01-24',NULL,2)
,(100,'2021-01-25',NULL,2),(100,'2021-01-26',NULL,2),(100,'2021-01-27',NULL,2),(100,'2021-01-28',NULL,2);
-- MAYBE ??
SELECT
emp_id,
dates,
day_one,
week_num_expected,
CASE
WHEN (ROW_NUMBER() OVER (ORDER BY dates ASC) - 1) / 7 = 0
OR
((ROW_NUMBER() OVER (ORDER BY dates ASC) - 1) / 7) % 2 = 0
THEN 1
ELSE 2
END AS week_num_by_code
FROM #table1
DROP TABLE #table1