Oracle regexp_replace pada kata-kata lengkap

Inilah salah satu cara untuk melakukannya - dengan kueri rekursif (memerlukan Oracle 11.2 atau lebih tinggi). Jangan berharap itu cepat.

with stg as
(
  select '(ofof+ol)' str from dual union all
  select '(oof+ol+of)'   from dual union all
  select '(*of + 2)'     from dual union all
  select '(of*of + 2)'   from dual 
),
rec ( str, lvl, new_str ) as
(
  select str, 1, upper(str)
    from stg
  union all
  select str, lvl + 1, 
         regexp_replace(new_str, '(\W|^)(OF)(\W|$)', '\1"OF"\3', 1, lvl)
  from   rec
  where  regexp_instr(new_str, '(\W|^)(OF)(\W|$)', 1, lvl) > 0
)
select str, new_str
from   rec
where  regexp_instr(new_str, '(\W|^)(OF)(\W|$)', 1, lvl) = 0
;

STR          NEW_STR          
------------ ------------------
(ofof+ol)    (OFOF+OL)         
(oof+ol+of)  (OOF+OL+"OF")     
(*of + 2)    (*"OF" + 2)       
(of*of + 2)  ("OF"*"OF" + 2)