The Relational Databases Connectors Extension provides a Thing Template to connect to the PostgreSQL which I configured as given in the User Guide that come with the extension. Gave the connection details of the PostgreSQL database server installed on the local machine. Created a service with SQL command, to connect to the database and access the tables, but while executing the service, it gave following error - [Unable to Invoke Service postgresql_service on PostgreThing : Connection to localhost:5432 refused. Check that the hostname and port are correct and that the postmaster is accepting TCP/IP connections]. Re-verified configuration settings, PostgreSQL server is also running, but still the error occurs. Suggestions needed, anybody who has used this extension?
Are you sure you are setting up the service right? You say here that you created a SQL command to connect to the database and access tables, but you need a SQL query if you are accessing tables or like just doing a SELECT or something similar. The SQL command scripting mode is for UPDATE, INSERT, DELETE, etc.
Hope this helps!