Is it possible for you to share your process and also the full log file content? It will really help us to find what is the issue in the connector configuration.
Also are you willing to store a form widget content or a step or process data? If the information is stored in step or process data you can include the variable name surrounded by ${ and } in your SQL query. Note that subscription edition of Bonita allow to use directly process data in connectors when submitting forms (and so avoid duplication of information).
Bonitasoft empowers development teams with Bonita, the open-source and extensible platform to solve the most demanding process automation use cases. The Bonita platform accelerates delivery of complex applications with clear separation between capabilities for visual programming and for coding. Bonita integrates with existing solutions, orchestrates heterogeneous systems, and provides deep visibility into processes across the organization.