Check if a field exists of not in a query

[Jean-Claude Antonio]

Hello,

Sorry if this question was already asked, but I could not find subjects 
related to it.
Is it possible in a query to check if a field exists of not.
something like:
myfield:EXIST
or myfield:ANY VALUE
I had a look at the Query Parser Syntax, and I could not find anything 
on the subject.

Thanks in advance.

*Jean-Claude Antonio*