How to Fix ORA-06530: Reference to Uninitialized Composite in Oracle

ORA-06530 is raised when PL/SQL code sets or reads an attribute of an object type variable that is still NULL. Declaring a variable of an object type does not create an object; until a constructor or a query assigns one, the variable is atomically null and has no attributes to set. The predefined exception is ACCESS_INTO_NULL. Call the constructor first.

Reproduce the Error

Example:

create type demo_point_t as object (x number, y number);
/
declare
  p demo_point_t;
begin
  p.x := 10;
end;
/

Output:

Type DEMO_POINT_T compiled

declare
*
ERROR at line 1:
ORA-06530: Reference to uninitialized composite
ORA-06512: at line 4

Fix: Initialize with the Constructor

Example:

set serveroutput on
declare
  p demo_point_t := demo_point_t(null, null);    -- constructor first
begin
  p.x := 10;
  p.y := 20;
  dbms_output.put_line(p.x || ', ' || p.y);
  dbms_output.put_line(case when p is null then 'null' else 'initialized' end);
end;
/

Output:

10, 20
initialized

PL/SQL procedure successfully completed.

The constructor DEMO_POINT_T(NULL, NULL) creates an object whose attributes are NULL, but the object itself is not, so its attributes can be set.

Things to Know

• A SELECT INTO of an object column, or a function returning the type, also initializes the variable.
• Test the object with IS NULL before using it when it may not be set, for example a parameter passed as NULL.
• Records declared with %ROWTYPE or TYPE ... IS RECORD do not need a constructor.

Related Guides

• How to Use Object Type Inheritance in Oracle
• What ORA-06512: At Line Means in Oracle and How to Find the Error

Conclusion

ORA-06530 means an object variable was used before it held an object. Assign it with the type's constructor, a query, or a function before setting attributes, and test IS NULL when it may be missing.