It means column MY_TYPE in table T where ID=10 is NULL. Another words there is no object for ID=10. Therefore your update is asking to set attribute of an object that does not exist and Oracle spits out an error:

SQL> CREATE OR REPLACE
2 TYPE MY_TYPE
3 IS OBJECT(ATTRIBUTE1 VARCHAR2(10),ATTRIBUTE2 VARCHAR2(10),ATTRIBUTE3 VARCHAR2(10));
4 /

Type created.

SQL> CREATE TABLE T(ID NUMBER,MY_TYPE MY_TYPE)
2 /

Table created.

SQL> INSERT INTO T VALUES(1,MY_TYPE('A','B','C'))
2 /

1 row created.

SQL> INSERT INTO T(ID) VALUES(10);

1 row created.

SQL> COMMIT
2 /

Commit complete.

SQL> UPDATE T p SET p.MY_TYPE.ATTRIBUTE1 = 'X'
2 WHERE p.ID = 1
3 /

1 row updated.

SQL> UPDATE T p SET p.MY_TYPE.ATTRIBUTE1 = 'X'
2 WHERE p.ID = 10
3 /
UPDATE T p SET p.MY_TYPE.ATTRIBUTE1 = 'X'
*
ERROR at line 1:
ORA-02309: atomic NULL violation


What to do depends on your business requirements. If you do not want to update object attribute if object does not exists use:

SQL> UPDATE T p SET p.MY_TYPE.ATTRIBUTE1 = 'X'
2 WHERE p.ID = 10
3 AND p.my_type IS NOT NULL
4 /

0 rows updated.

If you want to update object attribute when object exists and create object when it does not exist you need to issue two updates:

SQL> DROP TABLE T;

Table dropped.

SQL> CREATE TABLE T(ID NUMBER,MY_TYPE MY_TYPE);

Table created.

SQL> INSERT INTO T VALUES(10,MY_TYPE('A','B','C'));

1 row created.

SQL> INSERT INTO T(ID) VALUES(10);

1 row created.

SQL> COMMIT;

Commit complete.

SQL> SELECT * FROM T;

ID
-----------
MY_TYPE(ATTRIBUTE1, ATTRIBUTE2, ATTRIBUTE3)
--------------------------------------------------------------------------------
10
MY_TYPE('A', 'B', 'C')

10



SQL> UPDATE T p SET p.MY_TYPE.ATTRIBUTE1 = 'X'
2 WHERE p.ID = 10
3 AND p.my_type IS NOT NULL;

1 row updated.

SQL> SELECT * FROM T;

ID
-----------
MY_TYPE(ATTRIBUTE1, ATTRIBUTE2, ATTRIBUTE3)
--------------------------------------------------------------------------------
10
MY_TYPE('X', 'B', 'C')

10



SQL> UPDATE T p SET p.MY_TYPE = MY_TYPE('X',NULL,NULL)
2 WHERE p.ID = 10
3 AND p.my_type IS NULL;

1 row updated.

SQL> SELECT * FROM T;

ID
-----------
MY_TYPE(ATTRIBUTE1, ATTRIBUTE2, ATTRIBUTE3)
--------------------------------------------------------------------------------
10
MY_TYPE('X', 'B', 'C')

10
MY_TYPE('X', NULL, NULL)


Solomon Yakobson.