How to connect to JDBC database using SQL Gateway?

I have to connect to an external database and I'd like to use the JDBC SQL Gateway.

I followed this tutorial [1] to create a JDBC SQL Gateway and after configured it works as expected, but I don't know

how use this connection into source code. Maybe these other tutorial is related [2] and [3].

[1] http://docs.intersystems.com/latest/csp/docbook/DocBook.UI.Page.cls?KEY=...

[2] https://community.intersystems.com/product-documentation/intersystems-pr...

[3] http://docs.intersystems.com/latest/csp/documatic/%25CSP.Documatic.cls?A...

Thanks in Advance.