select LPR.ROLE_CODE 
from LEGAL_PERSON_ROLE LPR, ROLE R 
where LPR.ROLE_CODE = R.ROLE_CODE

SQL> create table t_role (id number primary key, r_name varchar2(20));

Table created.

SQL> create table t_legal_person_role (id number primary key,
  2                                    id_role number constraint fk_role references t_role (id));

Table created.

SQL> insert all
  2    into t_role (id, r_name) values (1, 'Role 1')
  3    into t_role (id, r_name) values (2, 'Role 2')
  4    into t_legal_person_role (id, id_role) values (100, 2)
  5  select * from dual;

3 rows created.

SQL> commit;

Commit complete.

SQL> delete from t_role where id = 1;

1 row deleted.

SQL> delete from t_role where id = 2;
delete from t_role where id = 2
*
ERROR at line 1:
ORA-02292: integrity constraint (SCOTT.FK_ROLE) violated - child record found


SQL>

DECLARE
   nb number;
BEGIN
    FOR ii IN 1 .. ApexLib_TabForm.getRowCount
    LOOP
       IF ApexLib_TabForm.isRowSelectorChecked(ii)
       THEN 
           select count(*) into nb from LEGAL_PERSON_EXPERTISE_AREA 
           where EXPERTISE_AREA_ID = ApexLib_TabForm.NV('EXPERTISE_AREA_ID', ii);
           IF nb > 0
           THEN
               ApexLib_Error.addError
                 ( pError      => 'Expertise Area cannot be deleted'
                 , pColumnName => 'EXPERTISE_AREA_NAME'
                 , pRow        => ii
                 );

           END IF;
       END IF;
    END LOOP;
    --
    RETURN ApexLib_Error.getErrorStack;
END;

DECLARE
   nb number;
BEGIN
    FOR ii IN 1 .. ApexLib_TabForm.getRowCount
    LOOP
       IF ApexLib_TabForm.isRowSelectorChecked(ii)
       THEN 
           select count(*) into nb from LEGAL_PERSON_ROLE 
           where LEGAL_ROLE_CODE = ApexLib_TabForm.NV('LEGAL_ROLE_CODE', ii);
           IF nb > 0
           THEN
               ApexLib_Error.addError
                 ( pError      => 'Legal Role cannot be deleted'
                 , pColumnName => 'LEGAL_ROLE_NAME'
                 , pRow        => ii
                 );

           END IF;
       END IF;
    END LOOP;
    --
    RETURN ApexLib_Error.getErrorStack;
END;