Assuming your form is already developed with two input fields…then the next step in the workflow would be to submit an access request for a dummy entitlement, with clientMetadata:
clientMetadata would hold the field1value and field2value.
Then, in the (1) JDBC Provisioning Rule, and then (2) fetch the clientMetadata…and handle the rest of your statement handling from there. (If dummy entitlement is in the request…then do this other thing instead)