Function may not be use in SQL - PLS-00231

Question

Here is my code,
-- Database 10g Enterprise Edition Release 10.2.0.2.0
declare
v1 varchar2(2000);
function test_func ( v2 varchar2) return varchar2
is
begin
return v2 || 'x' || v2;
end;
begin
-- ok
v1 := test_func('Hello');
--- Error PLS-00231: Function may not be used
--insert into xxxx values test_func(….
select test_func('World') into v1 from dual;
end;
I don’t want to define test_func in database as a stand-alone/package function. Is there any other way in 10G.
Thanks.

Answer 1

Works for me...
SQL> select banner from v$version;
BANNER
Oracle Database 10g Enterprise Edition Release 10.2.0.3.0 - 64bi
PL/SQL Release 10.2.0.3.0 - Production
CORE 10.2.0.3.0 Production
TNS for Solaris: Version 10.2.0.3.0 - Production
NLSRTL Version 10.2.0.3.0 - Production
SQL> set serverout on
SQL> declare
2 v1 varchar2(2000);
3 function test_func ( v2 varchar2) return varchar2
4 is
5 begin
6 return v2 || 'x' || v2;
7 end;
8 begin
9 -- ok
10 v1 := test_func('Hello');
11 dbms_output.put_line (v1);
12 end;
13 /
HelloxHello
PL/SQL procedure successfully completed.