<variable variable_name data_type;>

example <variable dusko number;> 

Well, as the output says, these are unsupported!

Note that PL/SQL variables in SQL are bind variables. So depending on what you're trying to do you can "use bind variables" by placing the query in a PL/SQL block.

For example:

declare
  var int;
begin
  select ...
  where  col = var;
end;

In this instance, VAR is a bind variable for the query. If you explain in more detail why you want to use bind variables we may be able to help with other options.

In general - if you have comments or suggestions for Live SQL, please use the feedback option on that site.