DECLARE

c   INT;
ok  INT;

BEGIN

  FOR crec IN (SELECT * FROM table_name)
    LOOP
      c:= dbms_sql.open_cursor();
      DBMS_SQL.PARSE(c,crec.clob_field,1);
      ok:= dbms_sql.execute(c);
      dbms_sql.close_cursor(c);
    END LOOP;
  COMMIT;
  
  EXCEPTION when others THEN null;

END;

SQL> create table t_clob (clob_field clob);

Table created.

SQL> insert into t_clob values('begin null; end;');

1 row created.

SQL> commit;

Commit complete.

SQL> select * from t_clob;

CLOB_FIELD
--------------------------------------------------------------------------------
begin null; end;

SQL> DECLARE
  2  
  3  c   INT;
  4  ok  INT;
  5  
  6  BEGIN
  7  
  8    FOR crec IN (SELECT clob_field FROM t_clob)
  9      LOOP
 10        c:= dbms_sql.open_cursor();
 11        DBMS_SQL.PARSE(c,crec.clob_field,1);
 12        ok:= dbms_sql.execute(c);
 13        dbms_sql.close_cursor(c);
 14    END LOOP;
 15  
 16  END;
 17  /

PL/SQL procedure successfully completed.

SQL> update t_clob set clob_field = 'begin polnaya hren; end;';

1 row updated.

SQL> commit;

Commit complete.

SQL> DECLARE
  2  
  3  c   INT;
  4  ok  INT;
  5  
  6  BEGIN
  7  
  8    FOR crec IN (SELECT clob_field FROM t_clob)
  9      LOOP
 10        c:= dbms_sql.open_cursor();
 11        DBMS_SQL.PARSE(c,crec.clob_field,1);
 12        ok:= dbms_sql.execute(c);
 13        dbms_sql.close_cursor(c);
 14    END LOOP;
 15  
 16  END;
 17  /
DECLARE
*
ERROR at line 1:
ORA-06550: line 1, column 15:
PLS-00103: Encountered the symbol "HREN" when expecting one of the following:
:= . ( @ % ;
The symbol ":=" was substituted for "HREN" to continue.
ORA-06512: at "SYS.DBMS_SYS_SQL", line 906
ORA-06512: at "SYS.DBMS_SQL", line 39
ORA-06512: at line 11


SQL> DECLARE
  2  
  3  c   INT;
  4  ok  INT;
  5  
  6  BEGIN
  7  
  8    FOR crec IN (SELECT clob_field FROM t_clob)
  9      LOOP
 10        c:= dbms_sql.open_cursor();
 11        DBMS_SQL.PARSE(c,crec.clob_field,1);
 12        ok:= dbms_sql.execute(c);
 13        dbms_sql.close_cursor(c);
 14    END LOOP;
 15  
 16    EXCEPTION WHEN others THEN null;
 17  
 18  END;
 19  /

PL/SQL procedure successfully completed.

SQL> DECLARE
2 
3 c INT;
4 ok INT;
5 
6 BEGIN
7 
8 FOR crec IN (SELECT * FROM table_name)
9 LOOP
10 c:= dbms_sql.open_cursor();
11 dbms_sql.parse(c,crec.clob_field,1);
12 ok:= dbms_sql.execute(c);
13 dbms_sql.close_cursor(c);
14 END LOOP;
15 COMMIT;
16 
17 END;
18 /
DECLARE
*
ошибка в строке 1:
ORA-00955: имя уже задействовано для существующего объекта
ORA-06512: на "SYS.DBMS_SYS_SQL", line 906
ORA-06512: на "SYS.DBMS_SQL", line 39
ORA-06512: на line 11