[Zope] dtml-if based on result from zsql method

[Mariusz Błoński]

I try to write zsql method with behaviour based on result from another zsql
method (simple select count(x) from table where x=...). 
If there are records for x i want to do something, but if not, something
else. I tried to write something like that (x is an parameter of both zsql
methods):
<dtml-call zsql_count>
<dtml if expr="">
something
<dtml-else>
something else
</dtml-if>

I dont know what to write as <dtml-if> expression.

Mariusz