Concatenation Question

[WWRA]

Despite all my searches and using my Discoverer Handbook, I can't get the following concatenation to work as desired:
CONCAT(Last Name,First Name)
The problem is how can I get a space between the last name and the first name using concatenation? I've tried numerous things, no luck.

TIA
New to Discoverer

 

[lewisp]

Try [tt]last_name || ' ' || first_name[/tt]

 

[Gardezi]

CONCAT(CONCAT(LAST_NAME,' '),FIRST_NAME)

 

[WWRA]

Many thanks to lewisp & Gardezi....by using your suggestions I got it to work.