Return SQL Sub Query with a variable inside Select - sql

Question

My Application is a cash register. The following query takes a TransactionID and returns one or more rows of items sold in this single transaction i.e. for TransactionID = 28715:
DECLARE #SalesItems varchar(250);
DECLARE #TransactionID int;
SET #TransactionID = 28715;
Select #SalesItems = coalesce(#SalesItems + ', ', '') + CAST(TransactionsPosLines.Description as varchar(250))
From
TransactionsPosLines
where TransactionsPosLines.TransactionId = #TransactionID
select #SalesItems
and returns:
"Widget A, Widget B, Widget C" as a single string.
I also have an end of day transaction report which I want to append the string (Widget A etc...) onto the end of the transaction report.
Select
Transactions.TransactionId,
Transactions.TransactionDate,
Transactions.MoneyIn,
Transactions.MoneyOut,
Transactions.Description,
PaymentMethods.PaymentMethodName,
Transactions.TransactionRef,
Membership.Username,
Tills.Description As 'Till Name',
Transactions.Reason,
-- FOR THIS LAST COLUMN HERE I WANT TO SHOW THE OUTPUT OF THE QUERY ABOVE
====> SalesItems
From
Transactions Left Outer Join
Tills
On Transactions.TillId = Tills.TillId Inner Join
PaymentMethods
On Transactions.PaymentMethodId = PaymentMethods.PaymentMethodsID Inner Join
Membership
On Transactions.UserId = Membership.UserId Inner Join
Where
Transactions.TransactionDate >= #DateStart And
Transactions.TransactionDate <= #DateEnd
So when I run this report I get something like this:
TransactionId TransactionDate MoneyIn MoneyOut Description PaymentMethodName TransactionRef Username Till Name Reason SalesItems
28715 31/08/2016 09:07 119.99 0 Sale - Card Card 24881 Chantal Till1 Null Widget A, Widget B, Widget C

Answer 1

CROSS APPLY WITH FOR XML CONCATENATION METHOD:
Select
t.TransactionId,
t.TransactionDate,
t.MoneyIn,
t.MoneyOut,
t.Description,
p.PaymentMethodName,
t.TransactionRef,
m.Username,
tl.Description As 'Till Name',
t.Reason,
c.SalesItems
From
Transactions t
LEFT JOIN Tills tl
ON t.TillId = tl.TillId
INNER JOIN PaymentMethods p
ON t.PaymentMethodId = p.PaymentMethodID
INNER JOIN Membership m
On t.UserId = m.UserId
CROSS APPLY
(SELECT STUFF(
(SELECT ',' + CAST(tp.Description AS VARCHAR(100))
FROM
TransactionPostLines tp
WHERE t.TransactionId = tp.TransactionId
FOR XML PATH(''))
,1,1,'') as SalesItems) c
Where
t.TransactionDate >= #DateStart
AND t.TransactionDate <= #DateEnd
AS Sub Select in column Definition:
Select
t.TransactionId,
t.TransactionDate,
t.MoneyIn,
t.MoneyOut,
t.Description,
p.PaymentMethodName,
t.TransactionRef,
m.Username,
tl.Description As 'Till Name',
t.Reason,
STUFF(
(SELECT ',' + CAST(tp.Description AS VARCHAR(100))
FROM
TransactionPostLines tp
WHERE t.TransactionId = tp.TransactionId
FOR XML PATH(''))
,1,1,'') as SalesItems
From
Transactions t
LEFT JOIN Tills tl
ON t.TillId = tl.TillId
INNER JOIN PaymentMethods p
ON t.PaymentMethodId = p.PaymentMethodID
INNER JOIN Membership m
On t.UserId = m.UserId
Where
t.TransactionDate >= #DateStart
AND t.TransactionDate <= #DateEnd
Note using table aliases makes the code easier to read and to write!

Answer 2

I have used cross apply in order to apply result to inner query to each row of your main query. Check whether this helps you:
Select
Transactions.TransactionId,
Transactions.TransactionDate,
Transactions.MoneyIn,
Transactions.MoneyOut,
Transactions.Description,
PaymentMethods.PaymentMethodName,
Transactions.TransactionRef,
Membership.Username,
Tills.Description As 'Till Name',
Transactions.Reason,
-- HERE >>
--SalesItems =
dt.salesItems
From
Transactions Left Outer Join
Tills
On Transactions.TillId = Tills.TillId Inner Join
PaymentMethods
On Transactions.PaymentMethodId = PaymentMethods.PaymentMethodsID Inner Join
Membership
On Transactions.UserId = Membership.UserId
cross apply (
select distinct stuff((
Select ',' + CAST(TransactionsPosLines.Description as varchar(250))
From
TransactionsPosLines
where TransactionsPosLines.TransactionId = Transactions.TransactionId
FOR XML PATH('')),1,1,'') as salesItems
) as dt
-- TransactionsPosLines
-- On TransactionsPosLines.TransactionId = Transactions.TransactionId
Where
Transactions.TransactionDate >= #DateStart And
Transactions.TransactionDate <= #DateEnd