Using a variable in Dynamic Query in SQL Server

Question

What I'm trying to do from this query is i'm trying to get all the rows which are older than the specified Cutoffnumber from customertransaction table:

@Cutoffnumber INT

SELECT @SQL = 'SELECT * FROM customertransaction WHERE DATEDIFF(DD, Transactiondate, GETDATE()) > @Cutoffnumber '

But i'm getting the below error, Note that this is a dynamic SQL query.

Must declare the scalar variable "@Cutoffnumber"

How should I go about.

Answer 1

Look into sp_executesql

Answer 2

Decalre @Cutoffnumber INT    
Set @Cutoffnumber = @someValue
SELECT @SQL = 'SELECT * FROM customertransaction WHERE DATEDIFF(DD, Transactiondate, GETDATE()) >' + @Cutoffnumber 

Though it seems like you could do this without dynamic SQL:

Declare @Cutoffnumber INT    
Set @Cutoffnumber = @someValue
SELECT * FROM customertransaction WHERE DATEDIFF(DD, Transactiondate, GETDATE()) > @Cutoffnumber