Database Connection in ADF BC 11g

My colleague was facing ADF BC development question and asked me to help. He sent me whole application, so I was able to open it directly with my local JDeveloper 11g. While investigating actual question, I noticed strange behavior in ADF BC. For example, attribute types were not recognized and I was getting log messages - oracle.jbo.domain.Number not found.

I started to dig more and I saw that Number type is displayed as oracle.jbo.domain.Number, usually it is shown just as Number:

I opened attribute editor, and I saw that type list gives only small set of types, Number type is not available:

Thats was strange and I was a bit frustrated. I realized that database connection is not defined and it might be a reason for this strange problem:

Database connection wasn't present because my colleague was using IDE level connection. I defined HrDS connection locally:

After IDE restart, it started to work properly - Number type was recognized again:

And types list was showing all available types:

This means, missing database connection definition was causing direct impact on ADF BC development.  If you will face same issue, make sure following files are present inside your application - .adf/META-INF/connections.xml, src/META-INF/cwallet.sso and src/META-INF/jps-config.xml.

Download sample application with database connection files in place - DatabaseConnectionADFBC.zip.

By the way, original question received from my colleague was solved as well ;-)