Is it possible to Update records in Database server using Data Direct Connector which creates external objects in salesforce application.
Our Salesforce Connect/external object support does support full CRUD operations. We released this capability when Salesforce added update support to Salesforce Connect.
We'd be happy to spend some time with you discussing our solutions for Salesforce Connect connectivity. (We offer both a SaaS solution and a self-hosted offering). It's very easy to do an evaluation - let us know if you're interested.