Microsoft Access: Why qdf.execute Is Not Showing Any Warning?

I had an application in which I had a code like

Dim qdf as QueryDef
qdf = new QueryDef("Query")
qdf.execute

The query was not running because of error but the application was not breaking at the time of error generation. To force the application to break/throw exception write the statement like

qdf.execute dbfailOnError

This way we can catch all errors.