Why is this an issue?
Unused parameters are misleading. Whatever the values passed to such parameters, the behavior will be the same.
Noncompliant code example
CREATE PROCEDURE SalesByCustomer
@CustomerName nvarchar(50) -- Noncompliant
AS
SELECT c.customer_name, sum(ctr.amount) AS TotalAmount
FROM customers c, contracts ctr
WHERE c.customer_id = ctr.customer_id
GROUP BY c.customer_name
ORDER BY c.customer_name
Compliant solution
CREATE PROCEDURE SalesByCustomer
@CustomerName nvarchar(50)
AS
SELECT c.customer_name, sum(ctr.amount) AS TotalAmount
FROM customers c, contracts ctr
WHERE c.customer_id = ctr.customer_id
AND c.customer_name = @CustomerName
GROUP BY c.customer_name
ORDER BY c.customer_name
