Originally posted by ken1212

i have allready created data in position table for position_id 27002
No you haven't, that's why you're getting this error. Most likely, your problem is with type mismatch. You are storing a char(8) in one table and a char(9) in another.

Note: If you're really storing numbers, use NUMBER data type.

Code:
SQL> desc job
 Name                                      Null?    Type
 ----------------------------------------- -------- ----------------------------
 JOB_NUMBER                                NOT NULL CHAR(8)
 DATE_CREATED                                       DATE
 DEPT_ID                                            CHAR(9)
 POSITION_ID                                        CHAR(9)

SQL> desc position
 Name                                      Null?    Type
 ----------------------------------------- -------- ----------------------------
 POSITION_ID                               NOT NULL CHAR(8)
 DESCRIPTION                                        VARCHAR2(50)
 DUTIES                                             VARCHAR2(50)
 SALARY                                             CHAR(15)
 LEVEL_NO                                           CHAR(15)

SQL> insert into position values (123, 'dude', 'all', 123, 15);

1 row created.

SQL> insert into job values (1, sysdate, 1, 123);
insert into job values (1, sysdate, 1, 123)
*
ERROR at line 1:
ORA-02291: integrity constraint (SYSTEM.FKPOSITION_ID) violated - parent key
not found


SQL> select '|' || position_id || '|' from position;

'|'||POSIT
----------
|123     |

SQL> alter table job disable constraint position_id;
alter table job disable constraint position_id
*
ERROR at line 1:
ORA-02431: cannot disable constraint (POSITION_ID) - no such constraint


SQL> alter table job disable constraint fkposition_id;

Table altered.

SQL> insert into job values (1, sysdate, 1, 123);

1 row created.

SQL> commit;

Commit complete.

SQL> select '|' || position_id || '|' from job;

'|'||POSITI
-----------
|123      |
notice position_id in job is 9 chars, in position is 8 chars.