Configuring sync lookup scenario without receiver

Hi experts,

I want to do the following scenario and I'm not sure, if this is possible:

I have a sync SOAP call to SAP PI. The request message is mapped to the response message of the sync call. Inside the message mapping, I'm executing a JDBC Lookup, which retrieves all necessary data and puts it into the response structure.

The response should be posted back to the caller. My difficulties are in configuring such a scenario, because there is no actual receiver.

Is there a way to do this in SAP PI? I can't use sync JDBC receiver channel, due to necessary JOIN statements in SELECT (I would have to use XML SQL and JOINS are not possible with that as far as I know).

Best Regards

Sven