Query is successfully executed in SQL Server but not in .NET - asp.net

Question

I wrote a query which is working fine in both .NET app and SQL Server.
But, when I was testing with wide parameters, I found that for that particular, it is not showing anything in .NET app but showing result in SQL Server.
I tried to google, no results with little strange. So, I am asking here.
This is my query:
SELECT DISTINCT
tblCustomers.customerID AS Customer#,
tblCustomers.firstName + ' ' + tblCustomers.surname AS Name,
tblCustomers.street AS Street,
tblCustomers.suburb AS Suburb,
tblCustomers.postCode AS Postcode,
tblCustomers.state AS State,
tblCustomers.country AS Country,
tblCustomers.phone AS [Phone No.],
tblCustomers.fax AS Fax,
tblCustomers.mobilePhone AS [Mobile Phone],
tblCustomers.email AS [E-mail]
FROM
tblCustomers
INNER JOIN
tblProduct_Backorder ON tblCustomers.customerID = tblProduct_Backorder.customerId
WHERE
(tblCustomers.customerID IN
(SELECT
customerId
FROM
tblProduct_Backorder AS tblProduct_Backorder_1
WHERE
(productId IN
(SELECT
productID
FROM
tblProducts
WHERE
(skuCode = 76761)
)
)
)
)
This query is not working for skuCode = 76761, but this one working fine in SQL Server.
Thanks.

Answer 1

You have really not enough information in you question for us to even start guessing what caused the problem. In the mean-time try this instead of your query:
SELECT c.customerID AS [Customer#],
c.firstName + ' ' + tblCustomers.surname AS Name,
c.street AS Street,
c.suburb AS Suburb,
c.postCode AS Postcode,
c.state AS State,
c.country AS Country,
c.phone AS [Phone No.],
c.fax AS Fax,
c.mobilePhone AS [Mobile Phone],
c.email AS [E-mail]
FROM dbo.tblCustomers c
WHERE EXISTS ( SELECT 1
FROM dbo.tblProduct_Backorder b
JOIN dbo.tblProduct p
ON b.productId = p.productId
WHERE p.skuCode = 76761
AND b.customerId = c.customerId );
If I understand your table relationships correctly, it will produce the same result while doing a lot less work.
For your original question you should also post the .net code. Also, what does "no results" mean? An empty result? A timeout? An error?

Answer 2

I found solution by help of xQbert's Comment. I took time and and saw how query is executed in SQL Profiler. skuCode in Table tblProduts is nvarchar(6) and in Table tblProduct_BackOrder its Integer. So, I converted into Integer for same Parameter using Convert() function.