How can we using DB Functions (Concat, Datepart, etc)

Hi All,

I am new to Pentaho. I have installed the trail version and trying to create a basic report.
My DB is Oracle XE 11 R2 and I was trying to concatenate firstname and lastname in Pentaho Metadata Editor (PME).
Unfortunately I was not able to find any way to perform this action.
Any kind of answers are appreciated.

Thank you