Calling Oracle sequences from within BO Data Services Designer

Hi - I just started using BO Data Services and I'm trying to reference an Oracle sequence within a Data Flow using a SQL transformation. The transformation is returning the next number from the Oracle sequence correctly, but it only makes the call once instead of calling the SQL transformation for every record being processed.

The Data Flow has the output from a Match transformation and the output from the SQL transformation going into a Query transformation. This Query transformation then writes to the Oracle target table. All of the records written to the table are getting the same Id returned from the SQL transformation instead of the Id incrementing for each record inserted.

It's probably something simple, but what am I missing here? Do I need to create a procedure in Oracle which gets the next sequence number and then somehow (I don't know how) call that procedure from within the Data Flow?

Any suggestions would be greatly appreciated.

Thanks