SQL: Set variable to a cell value inside a stored procedure - sql

Question

I am trying to store a single cell value from one table in a variable (inside a stored procedure), so I can use it to edit a value in another table, but I keep getting a MSG 201:
Procedure or function 'spBookReturn' expects parameter '#bookID', which was not supplied.
Every time I try to run the sp where it all should happen:
CREATE PROC spBookReturn
#loanID UNIQUEIDENTIFIER,
#bookID UNIQUEIDENTIFIER OUTPUT
AS
BEGIN
BEGIN TRANSACTION tBookReturn
UPDATE BorrowedMaterial SET returned = 1, returnedDate = GETDATE();
SET #bookID = (SELECT TOP 1 bookID FROM BorrowedMaterial WHERE loanID = #loanID ORBER BY returnedDate);
UPDATE Books SET nHome = nHome + 1 WHERE ID = #bookID;
COMMIT TRANSACTION tBookReturn;
END;
EXEC spBookReturn '546A444A-3D8D-412E-876D-2053D575B54F'
Does anyone know why the way I have defined the #bookID variable doesn't work and how I can make it work?
Thanks.
EDIT:
I got two tables: BorrowedMaterial that includes the attributes loanID, bookID, returned, returnedDate and a few others that's not relevant.
The other table is Books and it includes bookID, nHome but not the loanID.
So by giving only the loanID as an input, I would like to update the nHome. I am trying to grab bookID since it is the only thing the two attributes got in common and this is where the issues happen.
Side note: I removed the variable #custID it spawned by mistake.

Answer 1

All parameters for a procedure are Input parameters. If you declare a parameter as an OUTPUT parameter, it is still an input one, and if it doesn't have a default value must be supplied.
If you want the OUTPUT parameters to be option, which I personally find can be quite often, then give them a default value. I also add some additional logic to your procedure, as you should be using an TRY...CATCH and an ORDER BY in your query with a TOP.
CREATE PROC dbo.spBookReturn #loanID uniqueidentifier,
#bookID uniqueidentifier = NULL OUTPUT,
#custID uniqueidentifier = NULL OUTPUT
AS
BEGIN
BEGIN TRY --If you are using tranasctions, make sure you have a ROLLBACK and THROW for errors
BEGIN TRANSACTION tBookReturn
UPDATE BorrowedMaterial
SET returned = 1,
returnedDate = GETDATE()
WHERE loanID = #loanID;
/*
UPDATE BorrowedMaterial
SET returnedDate = GETDATE()
WHERE loanID = #loanID;
*/
SET #bookID = (SELECT TOP 1 bookID
FROM BorrowedMaterial
WHERE loanID = #loanID
ORDER BY ???); --A TOP should have an ORDER BY
UPDATE Books
SET nHome = nHome + 1
WHERE ID = #bookID;
COMMIT TRANSACTION tBookReturn;
END TRY
BEGIN CATCH
ROLLBACK TRANSACTION tBookReturn;
THROW;
END CATCH;
END;
Then you can execute the procedure as you have, without #bookID and #custID being passed. Of course, if you don't, their values will be "lost" in the calling statement. If you need them, then pass their values too in the EXEC:
DECLARE #bookID uniqueidentifier, #CustID uniqueidentifier;
EXEC dbo.spBookReturn #loanID, #bookID OUTPUT, #CustID OUTPUT;
--SELECT #bookID, #CustID;

Answer 2

declare #bookID UNIQUEIDENTIFIER;
declare #custID UNIQUEIDENTIFIER;
declare #InResult;
exec #InResult= spBookReturn '546A444A-3D8D-412E-876D-2053D575B54F',#bookID,#custID;
select #bookID,#custID;
Seems, you need something like this

Answer 3

My take on what you're looking for. Because there are multiple DML statements (2 Updates) in a single transaction the XACT_ABORT ON option ensures a complete rollback. Also, the THROW in the CATCH block is placed before the ROLLBACK to preserve the SQL generated error metadata. Prior to executing the proc the OUTPUT variables are declared and placed in the parameter list (this omission is what was causing the initial error).
drop proc if exists dbo.spBookReturn;
go
CREATE PROC dbo.spBookReturn
#loanID uniqueidentifier,
#bookID uniqueidentifier OUTPUT,
#custID uniqueidentifier OUTPUT
AS
set nocount on;
set xact_abort on;
BEGIN TRANSACTION tBookReturn
BEGIN TRY
declare #ins_bm table(book_id uniqueidentifier,
cust_id uniqueidentifier);
UPDATE BorrowedMaterial
SET returned = 1,
returnedDate = GETDATE()
output inserted.book_id, inserted.cust_id into #ins_bm
WHERE loanID = #loanID;
if ##rowcount=0
begin
select #bookID=0,
#custID=0;
throw 50000, 'No update performed', 1;
end
else
begin
UPDATE b
SET nHome = nHome + 1
from Books b
WHERE exists (select 1
from #ins_bm bm
where b.ID = bm.book_id);
select top(1) #bookID=book_id,
#custID=cust_id
from #ins_bm;
end
COMMIT TRANSACTION tBookReturn;
END TRY
BEGIN CATCH
THROW
ROLLBACK TRANSACTION tBookReturn;
END CATCH;
go
declare #bookID UNIQUEIDENTIFIER;
declare #custID UNIQUEIDENTIFIER;
declare #InResult int;
exec #InResult=spBookReturn '546A444A-3D8D-412E-876D-2053D575B54F', #bookID output, #custID output;
select #bookID, #custID;

Answer 4

Thanks to #Larnu I figured out the only thing missing was a = on line 3 (and thanks to #charlieface I also got my code cleaned up a tiny bit):
CREATE PROC spBookReturn
#loanID UNIQUEIDENTIFIER,
#bookID UNIQUEIDENTIFIER = NULL OUTPUT
AS
BEGIN
BEGIN TRANSACTION tBookReturn
UPDATE BorrowedMaterial SET returned = 1, returnedDate = GETDATE();
SET #bookID = (SELECT TOP 1 bookID FROM BorrowedMaterial WHERE loanID = #loanID
ORDER BY returnedDate);
UPDATE Books SET nHome = nHome + 1 WHERE ID = #bookID;
COMMIT TRANSACTION tBookReturn;
END;
EXEC spBookReturn '546A444A-3D8D-412E-876D-2053D575B54F'