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 The Oracle PL/SQL SELF_IS_NULL Exception      [Return To Index] Jump to:  
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Term: SELF_IS_NULL

Definition:
In Oracle PL/SQL, SELF_IS_NULL is a system defined exception. The error number associated with the exception is -30625. Oracle server implicitly raises this exception when the program tries to call a MEMBER function for a NULL or a non initialized object instance. The built-in parameter SELF points to the object, and is always the first parameter passed to a MEMBER method.

Example Usage:

The example below shows an object table MEM_TAB holding instances of MEM_TYPE object type. The member procedure SHOW_NAME displays value of "name" attribute of the object instance. If the member method is invoked for a non initialized instance, Oracle raises the ORA-30625 exception i.e. SELF_IS_NULL

SQL> CREATE TYPE MEM_TYPE AS OBJECT (
idno NUMBER,
name VARCHAR2(20),
MEMBER PROCEDURE SHOW_NAME ( SELF IN OUT NOCOPY MEM_TYPE ));
/

Type created.

SQL> CREATE TYPE BODY MEM_TYPE AS
MEMBER PROCEDURE SHOW_NAME ( SELF IN OUT NOCOPY MEM_TYPE ) IS
BEGIN
DBMS_OUTPUT.PUT_LINE(TO_CHAR(idno) || ' ' || name);
END;
END;
/

Type body created.

SQL> CREATE TABLE MEM_TAB OF MEM_TYPE;

Table created.

SQL> INSERT INTO MEM_TAB VALUES (MEM_TYPE(1, 'PSOUG') );

1 row created.

SQL> SELECT VALUE(p) FROM MEM_TAB p WHERE p.name = 'PSOUG';

VALUE(P)(IDNO, NAME)
-------------------------------
MEM_TYPE(1, 'PSOUG')

SQL> DECLARE
L_TEST MEM_TYPE;
BEGIN
SELECT VALUE(p) INTO L_TEST FROM MEM_TAB p WHERE p.idno = 1;
L_TEST.SHOW_NAME();
END;
/
1 PSOUG

PL/SQL procedure successfully completed.


SQL> DECLARE
L_TEST MEM_TYPE;
BEGIN
L_TEST.SHOW_NAME();
END;

DECLARE
*
ERROR at line 1:
ORA-30625: method dispatch on NULL SELF argument is disallowed
ORA-06512: at line 4


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