Use Variable value in a SELECT statement - sql

Question

i have declared a variable #S and i am storing a sub query value in it which is returning more than one record , now what i want is to use it in a select statement , can i do that is it possible,
here is my query what i was trying but getting an error Must declare the scalar variable "#S"
Declare #S AS NVarchar(MAX)
SET #S = '(SELECT es.FirstName FROM [User] es WHERE es.UserId IN (SELECT CustomerUserID FROM OrderInfo))'
SELECT
OrderInfoId,
BorrowerFirstName As ConsumerFirstName,
BorrowerLastName As ConsumerLastName,
RequestedURL,
Requests,
SELECT #S,
u.FirstName +'' ''+ u.LastName As Affiliate,
o.RequestDateTime As DateOfTransaction,
o.RequestIPAddress As OriginatingIPAddress,
o.Requests As Status
from orderInfo o
inner join [User] u on o.AffiliateId = u.UserId
is it possible to do that. any help will be appreciated

Answer 1

If you want to append as a single string the result of the sub-query to every row produced by the main query, then, first of all you have to initialize #S:
Declare #S AS NVarchar(MAX) = ''
then properly set it:
SELECT #S = #S + ' ' + es.FirstName
FROM [User] es
WHERE es.UserId IN (SELECT CustomerUserID FROM OrderInfo)
and finally consume its contents in the main query:
SELECT
OrderInfoId,
BorrowerFirstName As ConsumerFirstName,
BorrowerLastName As ConsumerLastName,
RequestedURL,
Requests,
(SELECT #S),
u.FirstName +'' ''+ u.LastName As Affiliate,
o.RequestDateTime As DateOfTransaction,
o.RequestIPAddress As OriginatingIPAddress,
o.Requests As Status
from orderInfo o
inner join [User] u on o.AffiliateId = u.UserId

Answer 2

Your biggest issue is that you're trying to select multiple rows into a single column. This can't be done. You will need to concatenate the FirstNames into a single value. There are a few ways to do this. One popular way is to use STUFF with FOR XML This is an example of how you would get all of the FirstNames that match your sub query into a column. The names will be comma separated.
SELECT
OrderInfoId,
BorrowerFirstName AS ConsumerFirstName,
BorrowerLastName AS ConsumerLastName,
RequestedURL,
Requests,
STUFF((SELECT
', ' + es.FirstName
FROM
[User] es
WHERE
es.UserId IN (SELECT
CustomerUserID
FROM
OrderInfo)
ORDER BY
es.FirstName
FOR
XML PATH('')
),1,2,'') AS CustomerFirstNames,
u.FirstName + ' ' + u.LastName AS Affiliate,
o.RequestDateTime AS DateOfTransaction,
o.RequestIPAddress AS OriginatingIPAddress,
o.Requests AS Status
FROM
orderInfo o
INNER JOIN [User] u ON o.AffiliateId = u.UserId
This seems a little strange too considering you're going to get ALL user first names that have a CustomerID in orderInfo. You might want to filter your sub query by orderInfo.Id or something.
Are you sure you're not just trying to get the CustomerID first name? You can join to [User] again to get this information.
SELECT
OrderInfoId,
BorrowerFirstName AS ConsumerFirstName,
BorrowerLastName AS ConsumerLastName,
RequestedURL,
Requests,
cu.FirstName AS Customer,
u.FirstName + ' ' + u.LastName AS Affiliate,
o.RequestDateTime AS DateOfTransaction,
o.RequestIPAddress AS OriginatingIPAddress,
o.Requests AS Status
FROM
orderInfo o
INNER JOIN [User] u ON o.AffiliateId = u.UserId
INNER JOIN [User] cu ON o.CustomerUserID = cu.UserId

Answer 3

you need to make the entire sql statement a string, and use sp_executesql like so:
DECLARE #OrderID int;
SET #ParmDefinition = N'#SubQuery varchar(255), '+
'#OrderInfoOUT varchar(30) OUTPUT';
SET #S = '(SELECT es.FirstName FROM [User] es WHERE es.UserId IN (SELECT CustomerUserID FROM #OrderInfoOUT = OrderInfo))';
SET #SQL =' OrderInfoId, '+
'BorrowerFirstName As ConsumerFirstName, '+
'BorrowerLastName As ConsumerLastName, '+
'RequestedURL, '+
'Requests, '+
#SubQuery+', '+
'u.FirstName +''' '''+ u.LastName As Affiliate, '+
'o.RequestDateTime As DateOfTransaction, '+
'o.RequestIPAddress As OriginatingIPAddress, '+
'o.Requests As Status'+
'from orderInfo o '+
'inner join [User] u on o.AffiliateId = u.UserId';
sp_executesql #SQL, #ParmDefinition, #SubQuery=#S, #OrderIDOUT=OrderID OUTPUT;
Then you can store the results in variables as I've show with OrderInfoOUT

Answer 4

You won't be able to run it this way. You would need something like sp_executesql

Answer 5

I believe there is a mix of concepts in your question: dynamic SQL with table variables.
If you're using SQL Server 2008 or uper, you have a choice to create table variables that keep alives for the period the hosting routine is running.
You can define something similar to this:
DECLARE #UserInfo TABLE
(
FirstName varchar(50) NOT NULL
);
Load the information as follows:
INSERT #UserInfo
SELECT es.FirstName
FROM [User] es
WHERE es.UserId IN (SELECT CustomerUserID FROM OrderInfo)
Finally you can join table variables similar as temporal tables based on your needs.