query a table multiple times for different date ranges - sql

Question

I have a table with records dating back 3 years that is continuously updated with new records and back filled for prior weeks.
I would like to create a result set that looks like the example below, where the columns 1,2,3,4, etc represent a specific week of the year. As data gets inserted, I would be able to add more columns for each week. I would like to run each date range every time I run this report because data is often entered for prior dates, so prior weeks will change.
location
name
wk1_hours
wk2_hours
wk3_hours
USA
John S
56.39
14.01
73.55
USA
Alex P
24.36
22.47
NULL
USA
Christine H
NULL
78.27
42.37
Canada
John S
40.32
NULL
22.58
Canada
Eric B
53.00
3.44
27.84
Mexico
Charles T
10.58
8.48
NULL
This is the query I have so far, how do I apply multiple date range variables to this query and to separate columns?
declare #wk1start as datetime
declare #wk1end as datetime
set #wk1start = '2022/7/4 00:00:00'
set #wk1end = '2022/7/10 23:59:59'
select
location,
name,
cast(hours as numeric (36,2)) as wk1_hours
from table
where name is not null
and date_of_service between #wk1start and #wk1end
group by
location

Answer 1

First let's slap together some test data. Providing example DDL and DML is very helpful when you ask questions like this:
DECLARE #TABLE TABLE (Location NVARCHAR(50), Name NVARCHAR(50), Date DATE, Hours INT)
INSERT INTO #TABLE (Location, Name, Date, Hours) VALUES
('USA', 'John S', '2022-12-01', 10),('USA', 'John S', '2022-12-02', 10),('USA', 'John S', '2022-12-03', 10),('USA', 'John S', '2022-12-04', 10),('USA', 'John S', '2022-12-05', 10),
('USA', 'Alex P', '2022-12-01', 5),('USA', 'Alex P', '2022-12-02', 5),('USA', 'Alex P', '2022-12-03', 5),('USA', 'Alex P', '2022-12-04', 5),('USA', 'Alex P', '2022-12-05', 5),
('USA', 'Christine H', '2022-12-01', 5),('USA', 'Christine H', '2022-12-02', 5),('USA', 'Christine H', '2022-12-03', 5),('USA', 'Christine H', '2022-12-04', 5),('USA', 'Christine H', '2022-12-05', 5)
INSERT INTO #TABLE (Location, Name, Date, Hours)
SELECT Location, Name, DATEADD(YEAR, -1, Date), Hours / 2
FROM #TABLE
UNION ALL
SELECT Location, Name, DATEADD(YEAR, -2, Date), Hours / 2
FROM #TABLE
I just threw some off the cuff values in the table, and then manipulated it to get a couple more years for the same dates.
You can use this data to mock up something similar to what you have as the desired output using some aggregation using the DATEPART function and then PIVOT like this:
SELECT a.Location, Week, a.Name, a.WeekOne, a.WeekTwo, a.WeekThree
FROM (
SELECT Location, Name, DATEPART(WEEK,Date) AS Week,
SUM(CASE WHEN DATEPART(YEAR,Date) = 2020 THEN Hours END) OVER (PARTITION BY Location, Name, DATEPART(WEEK,Date) ORDER BY (SELECT 1)) AS WeekOne,
SUM(CASE WHEN DATEPART(YEAR,Date) = 2021 THEN Hours END) OVER (PARTITION BY Location, Name, DATEPART(WEEK,Date) ORDER BY (SELECT 1)) AS WeekTwo,
SUM(CASE WHEN DATEPART(YEAR,Date) = 2022 THEN Hours END) OVER (PARTITION BY Location, Name, DATEPART(WEEK,Date) ORDER BY (SELECT 1)) AS WeekThree
FROM #TABLE
) a
GROUP BY a.Location, a.Name, Week, a.WeekOne, a.WeekTwo, a.WeekThree
Location Name weekNumber weekOne weekTwo weekThree
-------------------------------------------------------------
USA Alex P 49 10 8 15
USA Christine H 49 10 8 15
USA John S 49 25 20 30
This does make some assumptions. You say 'specific week of the year' which I inferred to mean the ISO week number (1-53). If that's not the case, you can group by what ever definition you need instead.
If you're not a fan of PIVOT then you could instead have some fun with windowed functions:
SELECT a.Location, Week, a.Name, a.WeekOne, a.WeekTwo, a.WeekThree
FROM (
SELECT Location, Name, DATEPART(WEEK,Date) AS Week,
SUM(CASE WHEN DATEPART(YEAR,Date) = 2020 THEN Hours END) OVER (PARTITION BY Location, Name, DATEPART(WEEK,Date) ORDER BY (SELECT 1)) AS WeekOne,
SUM(CASE WHEN DATEPART(YEAR,Date) = 2021 THEN Hours END) OVER (PARTITION BY Location, Name, DATEPART(WEEK,Date) ORDER BY (SELECT 1)) AS WeekTwo,
SUM(CASE WHEN DATEPART(YEAR,Date) = 2022 THEN Hours END) OVER (PARTITION BY Location, Name, DATEPART(WEEK,Date) ORDER BY (SELECT 1)) AS WeekThree
FROM #TABLE
) a
GROUP BY a.Location, a.Name, Week, a.WeekOne, a.WeekTwo, a.WeekThree
I think this is a little easier to read, and lends itself to using parameters better than the pivot method, but you're still stuck with manual columns.
Location Week Name WeekOne WeekTwo WeekThree
---------------------------------------------------------
USA 49 Alex P 10 8 15
USA 50 Alex P NULL 2 10
USA 49 Christine H 10 8 15
USA 50 Christine H NULL 2 10
USA 49 John S 25 20 30
USA 50 John S NULL 5 20