SSIS User Variable is not getting updated via SQL Task

Hi,

My package contains a User variable "User::IncrementalDate" String type.

I am using below query in SQL Task to update this variable:

Select ? = incremental_date from dbo.Audit where tablename = 'Sales'

In parameter mapping I use VARCHAR datatype for the variable and set parameter name as 0.

The sql task executes successfully but th evariable is not getting updated. Can anyone suggest solution for it.

Thank you.