CB Query Field supports substitutions so I suppose you could put an IF statement in it or add to the WHERE condition of your query to check the viewing users ID (use complex substitution with operator to specify user="#me") is not zero. More on substitutions at following URL.

www.allmysocials.com/tutorials/item/233-substitution-usage

Believe it would just be easier to put the field on a tab only viewable to Registered users. Don't know what connession is so can't comment further.

At any rate CB Query Field is NOT searchable. Searching is done directly to database values, being a field that dynamically builds it's values it is not searchable. Will be reviewing possibility to add searching support, but at this point am not sure if is possible.

Thanks for reply krileon. I just need a field that can show the degree of connession when I visit someone elase profile...

Then CB Query Field can do this.

I'm not sure I've understood it very well: can I do it without CB Query plugin?

Yes.

How can I do it? can you please show me the sintax?

You make a new field within field management of query type then you supply a SELECT query to display the results. For example the following.

The above would cause the field to render whatever the contents of cb_myfield is for example.

No, I don't know what connession is or where you're storing this information. Simply put you just make a database SELECT query, that is all. CB Query Field will render the SELECT queries results. More on database query usage can be found at the below link.

dev.mysql.com/doc/refman/5.0/en/index.html