No ... The PB2017Rx versions of PowerBuilder can only "consume" RESTful web services and not publish them (that is the bad news). However, the great news today is that you canbuild & publish RESTFul web services in the new and upcoming PB2019 version. The other really exciting news is that you can take the PB2019 beta out for a test driveright now ... https://www.appeon.com/developers/pb-2019-beta.html
FYI: Only SQL Server, Oracle and PostgreSQL will be supported in PB2019's C# Web API feature. Other DBMS may be added in later releases if the vendor(s) can supply .Net Core DB drivers. Appeon will also be looking at possibly adding .Net Framework ODBC support as another alternative in later release after PB2019 GA. However, this alternative is not under development at the current time.