Passing array as input to procedure

Question

Hi,
       create or replace type t_employee_id is table of number;
      create or replace type t_employee_name  is table of varchar2(4000);
I have created type for array input.
declare
  p_id t_employee_id;
  p_name t_employee_name;
begin
   p_id(1):=12;
  p_name(1):='no22';
p_id(2):=300;
p_name(2):='XXX';
p_id(3):=4;
p_name(3):='bn';
  sp_sample(p_id => p_id,
            p_name => p_name);
end;
CREATE OR REPLACE PROCEDURE sp_sample(p_id   IN t_employee_id,
                                      p_name IN t_employee_name) IS
  v_error EXCEPTION;
  PRAGMA EXCEPTION_INIT(v_error, -23456);
BEGIN
  FORALL i IN 1 .. p_id.COUNT SAVE EXCEPTIONS
    INSERT INTO employee
      (employee_id, employee_name)
    VALUES
      (p_id(i), p_name(i));
  COMMIT;
EXCEPTION
  WHEN v_error THEN
    FOR i IN 1 .. SQL%BULK_EXCEPTIONS.COUNT LOOP
      dbms_output.put_line('Error:' || SQL%BULK_EXCEPTIONS(i)
                           .ERROR_INDEX || 'Message' ||
                           SQLERRM(-sql%BULK_EXCEPTIONS(i).ERROR_CODE));
      dbms_output.put_line('\n');
    END LOOP;
END sp_sample;By compling the above code I getting error like this
ORA-06531-Reference to uninitialized collection.
Thanks in advance.

Answer 1

... and The Holly Book of All PL/SQL Programmers (also known as: Oracle® Database PL/SQL Language Reference) says:
Collection Initialization
Until you initialize it, a nested table or varray is atomically null; the collection itself is null, not its elements. To initialize a nested table or varray, you use a constructor, a system-defined function with the same name as the collection type. This function constructs collections from the elements passed to it.
You must explicitly call a constructor for each varray and nested table variable. Associative arrays, the third kind of collection, do not use constructors. Constructor calls are allowed wherever function calls are allowed.
Example 5-10 initializes a nested table using a constructor, which looks like a function with the same name as the collection type.
Example 5-10 Constructor for a Nested Table
DECLARE
TYPE dnames_tab IS TABLE OF VARCHAR2(30);
dept_names dnames_tab;
BEGIN
dept_names := dnames_tab('Shipping','Sales','Finance','Payroll');
END;
Because a nested table does not have a declared size, you can put as many elements in the constructor as necessary.------------------------------------------------------------------------------------------------------------------------------
It's very abstract and not intuitive but there is a difference between 'the collection is NULL (not initialized)' and 'the collection that is not NULL (initialized), but it has no elements' and 'the collection that has all elements NULL'. If you declare a variable of VARCHAR2(30) datatype then Oracle will allocate memory for this variable. However if you have a variable of a collection type then simply declaring it is not enough - you have to call a constructor so Oracle can allocate memory for this variable before it's first use.
So you can have:
declare
  p_id t_employee_id := t_employee_id();
  p_name t_employee_name := t_employee_name();
begin
   p_id(1):=12;
  p_name(1):='no22';
p_id(2):=300;
p_name(2):='XXX';
p_id(3):=4;
p_name(3):='bn';
  sp_sample(p_id => p_id,
            p_name => p_name);
end;or simply
declare
  p_id t_employee_id := t_employee_id (12, 300, 4);
  p_name t_employee_name := t_employee_name ('no22', 'XXX', 'bn') ;
begin
  sp_sample(p_id => p_id,
            p_name => p_name);
end;