firebird stored procedure

здр,
как може да се конкатенират два varchar-a в firebird stored procedure?
т.е. нещо от вида:

procedure(...)

tmp, somevariable varchar(xxx) - variables
somecondition integer - input parameter
result varchar(xxxx) - output parameter

for select somecolumn from sometable
where somefield = :somecondition
into :somevariable do begin
tmp := tmp + :somevariable;
end
result = tmp;
suspend
end
т.е suspend да върне като резултат somevariable1, somevariable2

procedure(...)

tmp, somevariable varchar(xxx) - variables
somecondition integer - input parameter
result varchar(xxxx) - output parameter
tmp='';
for select somecolumn from sometable
where somefield = :somecondition
into :somevariable do begin
tmp=:tmp||:somevariable;
end
result = tmp;
suspend
end

tks