Aggregate a subtotal column based on two dates of that same row - sql

Question

Situation:
I have 5 columns
id
subtotal (price of item)
order_date (purchase date)
updated_at (if refunded or any other status change)
status
Objective:
I need the order date as column 1
I need to get the subtotal for each day regardless if of the status as column 2
I need the subtotal amount for refunds for the third column.
Example:
If a purchase is made on May 1st and refunded on May 3rd. The output should look like this
+-------+----------+--------+
| date | subtotal | refund |
+-------+----------+--------+
| 05-01 | 10.00 | 0.00 |
| 05-02 | 00.00 | 0.00 |
| 05-03 | 00.00 | 10.00 |
+-------+----------+--------+
while the row will look like that
+-----+----------+------------+------------+----------+
| id | subtotal | order_date | updated_at | status |
+-----+----------+------------+------------+----------+
| 123 | 10 | 2019-05-01 | 2019-05-03 | refunded |
+-----+----------+------------+------------+----------+
Query:
Currently what I have looks like this:
Note: Timezone discrepancy therefore bring back the dates by 8 hours.
;with cte as (
select id as orderid
, CAST(dateadd(hour,-8,order_date) as date) as order_date
, CAST(dateadd(hour,-8,updated_at) as date) as updated_at
, subtotal
, status
from orders
)
select
b.dates
, sum(a.subtotal_price) as subtotal
, -- not sure how to aggregate it to get the refunds
from Orders as o
inner join cte as a on orders.id=cte.orderid
inner join (select * from cte where status = ('refund')) as b on o.id=cte.orderid
where dates between '2019-05-01' and '2019-05-31'
group by dates
And do I need to join it twice? Hopefully not since my table is huge.

Answer 1

This looks like a job for a Calendar Table. Bit of a stab in the dark, but:
--Overly simplistic Calendar table
CREATE TABLE dbo.Calendar (CalendarDate date);
WITH N AS(
SELECT N
FROM (VALUES(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL))N(N)),
Tally AS(
SELECT ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) -1 AS I
FROM N N1, N N2, N N3, N N4, N N5) --Many years of data
INSERT INTO dbo.Calendar
SELECT DATEADD(DAY, T.I, 0)
FROM Tally T;
GO
SELECT C.CalendarDate AS [date],
CASE C.CalendarDate WHEN V.order_date THEN subtotal ELSE 0 END AS subtotal,
CASE WHEN C.CalendarDate = V.updated_at AND V.[status] = 'refunded' THEN subtotal ELSE 0.00 END AS subtotal
FROM (VALUES(123,10.00,CONVERT(date,'20190501'),CONVERT(date,'20190503'),'refunded'))V(id,subtotal,order_date,updated_at,status)
JOIN dbo.Calendar C ON V.order_date <= C.CalendarDate AND V.updated_at >= C.CalendarDate;
GO
DROP TABLE dbo.Calendar;

Answer 2

Consider joining on a recursive CTE of sequential dates:
WITH dates AS (
SELECT CONVERT(datetime, '2019-01-01') AS rec_date
UNION ALL
SELECT DATEADD(d, 1, CONVERT(datetime, rec_date))
FROM dates
WHERE rec_date < '2019-12-31'
),
cte AS (
SELECT id AS orderid
, CAST(dateadd(hour,-8,order_date) AS date) as order_date
, CAST(dateadd(hour,-8,updated_at) AS date) as updated_at
, subtotal
, status
FROM orders
)
SELECT rec_date AS date,
CASE
WHEN c.order_date = d.rec_date THEN subtotal
ELSE 0
END AS subtotal,
CASE
WHEN c.updated_at = d.rec_date THEN subtotal
ELSE 0
END AS refund
FROM cte c
JOIN dates d ON d.rec_date BETWEEN c.order_date AND c.updated_at
WHERE c.status = 'refund'
option (maxrecursion 0)
GO
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