Plsql - an object-based table

Question

hi,
suppose I declared a type named Base with three attributes:
a,b,c.
Now I declare a type named Derived that inherites from Base. The type derived also has an additional attribute named d.
Now - When I declare a table that is based on the Derived type, the table consists of a,b,c,d in this order.
How can I make it to be: d,a,b,c ???
thanks.

Answer 1

"thanks, but a,b,c,d are not all numbers.
for instance - a is number, b is varchar2, c is a type that was pre-defined... "
And what is you confusion ? Quite the same:
SQL> create type base is object
  2  (a number, b varchar2(10), c arg_c)
  3  not final;
  4  /
&nbsp
Type created.
&nbsp
SQL> create or replace type derived
  2  under base (
  3  d date,
  4  constructor function derived (
  5  x1 date, x2 number, x3 varchar2, x4 arg_c)
  6  return self as result
  7  );
  8  /
&nbsp
Type created.
&nbsp
SQL> create or replace type body derived
  2  is
  3  constructor function derived (
  4  x1 date, x2 number, x3 varchar2, x4 arg_c)
  5  return self as result
  6  is
  7  begin
  8   self.d := x1;
  9   self.a := x2;
10   self.b := x3;
11   self.c := x4;
12   return;
13  end;
14  end;
15  /
&nbsp
Type body created.
&nbsp
SQL> declare
  2   obase derived := derived(sysdate,10,'Base',arg_c('New Object'));
  3  begin
  4   dbms_output.put_line('A is ' || obase.a);
  5   dbms_output.put_line('B is ' || obase.b);
  6   dbms_output.put_line('C is ' || obase.c.name);
  7   dbms_output.put_line('D is ' || obase.d);
  8  end;
  9  /
A is 10
B is Base
C is New Object
D is 11.07.05
&nbsp
PL/SQL procedure successfully completed.
SQL>/* Default constructor*/
SQL> create or replace type derived
  2  under base (
  3  d date
  4  );
  5  /
&nbsp
Type created.
&nbsp
SQL> declare
  2   obase derived := derived(10,'Base',arg_c('New Object'),sysdate);
  3  begin
  4   dbms_output.put_line('A is ' || obase.a);
  5   dbms_output.put_line('B is ' || obase.b);
  6   dbms_output.put_line('C is ' || obase.c.name);
  7   dbms_output.put_line('D is ' || obase.d);
  8  end;
  9  /
A is 10
B is Base
C is New Object
D is 11.07.05
&nbsp
PL/SQL procedure successfully completed.Rgds.