If you want to add data from a database into a spooled file via SQL, then you should consider these options:

1. Enrich spooled file from database workflow component inside your workflow.
2. You can also consider to use the ng:databaseLookup function for a spooled file within a transformation. Here you can e.g. transform a spooled file into another spooled file and at the same time add extra data into a new attribute
3. You can also add the extra SQL data into a spooled file line.
4. You can even add data into a new, hidden attribute in the spooled file.
5. After running this in the workflow you can refer to the extra data both in the workflow and in the designer and even save a copy of the changed contents with the To filesystem component.