Oracle PL/SQL Tutorial/Character String Functions/COMPOSE
compose("de" || unistr("\0300") )
SQL>
SQL>
SQL> select compose("de" || unistr("\0300") ) from dual;
dF
1 row selected.
SQL>
SQL>
SQL>
SQL> select compose("de" || unistr("\0300") ) from dual;
dF
1 row selected.
SQL>