Total of Totals in SQL Server - sql

Question

I have 3 tables -
Books -
BookNo BookName BookType
123 ABC 1
555 XYZ 0
Shelf
Shelf ShelfNo BookNo BookQuantity
XB XB01 123 5
XB XB02 555 3
XB XB03 123 8
BooksIssued
ShelfNo BookName IssuedDate QuantityIssued
XB01 ABC 11/21/2022 2
XB02 XYZ 11/20/2022 1
XB03 ABC 11/21/2022 5
My goal is to find out total number of books stock we have. The output should be grouped by book. And I have to combine all shelfNo which contain the same book and sum their Shelf.BookQuantity and then add it to BooksIssued.QuantityIssued for that particular book. Booktype should be displayed as Children for 0 and 1 for adults.
For example,
Output
BookNo BookName BookType Total Stock
123 ABC adults 20 //(5+8+2+5)
555 XYZ children 4 //(3+1)
So far, I have written this. I know I have chosen extra columns in my query than what I have mentioned in my output format. It is so because I was going step by step to understand the flow. I wanted to first group the data by book and sum the quantity but it isn't grouping the data by bookno . It is also not summing the bi.quantityissued.
select s.bookno, b.booktype, s.shelfno, b.bookname, s.bookquantity,
sum(bi.quantityissued), bi.issueddate
from Shelf s
left outer join BooksIssued bi on s.shelfno = bi.shelfno
left outer join Books b on s.bookno=b.bookno
where s.shelf = 'XB'
and bi.issueddate between '11/01/2022' and '11/07/2022'
group by s.bookno, s.shelfno, b.booktype, b.bookname, s.bookquantity, bi.issueddate
Please guide me what do I do next. Thank you.

Answer 1

This should do it:
WITH baseData As
(
SELECT BookNo, BookQty As Qty
FROM Shelf s
WHERE s.shelf = 'XB'
UNION ALL
SELECT b0.BookNo, QtyIssued As Qty
FROM BooksIssued bi
INNER JOIN Books b0 on b0.BookName = bi.BookName
WHERE bi.IssuedDate >= '20221101' AND bi.IssuedDate < '20221108'
),
grouped As
(
SELECT BookNo, Sum(Qty) As [Total Stock]
FROM baseData
GROUP BY BookNo
)
SELECT b.BookNo, b.BookName, b.BookType, g.[Total Stock]
FROM grouped g
INNER JOIN Books b ON b.BookNo = g.BookNo
This also shows one of the reasons (among several) the BooksIssued table should use BookNo instead of BookName: it would save you a join.
We can also write this with nested SELECT queries instead of the common table expressions (CTEs), but I find the CTE much easier to reason about:
SELECT b.BookNo, b.BookName, b.BookType, g.[Total Stock]
FROM (
SELECT BookNo, Sum(Qty) As [Total Stock]
FROM (
SELECT BookNo, BookQty As Qty
FROM Shelf s
WHERE s.shelf = 'XB'
UNION ALL
SELECT b0.BookNo, QtyIssued As Qty
FROM BooksIssued bi
INNER JOIN Books b0 on b0.BookName = bi.BookName
WHERE bi.IssuedDate >= '20221101' AND bi.IssuedDate < '20221108'
) baseData
GROUP BY BookNo
) g
INNER JOIN Books b ON b.BookNo = g.BookNo
This is still missing the adults vs children book type. You can fix this with a CASE expression, or using a Table Value Constructor. I prefer the latter here, because you can add many more types over time in an efficient way and because it sets you up to eventually use a real table, which is what you should have had in the first place:
WITH baseData As
(
SELECT BookNo, BookQty As Qty
FROM Shelf s
WHERE s.shelf = 'XB'
UNION ALL
SELECT b0.BookNo, QtyIssued As Qty
FROM BooksIssued bi
INNER JOIN Books b0 on b0.BookName = bi.BookName
WHERE bi.IssuedDate >= '20221101' AND bi.IssuedDate < '20221108'
),
grouped As
(
SELECT BookNo, Sum(Qty) As [Total Stock]
FROM baseData
GROUP BY BookNo
)
SELECT b.BookNo, b.BookName, bt.Name As BookType, g.[Total Stock]
FROM grouped g
INNER JOIN Books b ON b.BookNo = g.BookNo
INNER JOIN (VALUES (0, 'Childrens'), (1 'Adults') ) AS bt(Type, Name)
ON b.BookType = bt.Type;

Answer 2

Try this:
select bookno BookNo,
bookname BookName,
case booktype
when 1 then 'adults'
when 0 then 'children'
end BookType
SUM(TotalStock) TotalStock
from (
select b.bookno,
b.bookname,
b.booktype,
sum(bookquantity) TotalStock
from ..books b
inner join ..shelf s
ON b.bookno = s.bookno
group by b.bookno, b.bookname, b.booktype
UNION ALL
select b.bookno,
b.bookname,
b.booktype,
sum(QuantityIssued) TotalStock
from ..books b
inner join ..shelf s
ON b.bookno = s.bookno
inner join ..booksissued bi
ON s.shelfno = bi.shelfno
and b.bookname = bi.bookname
group by b.bookno, b.bookname, b.booktype
) s
group by bookno, bookname, booktype