Type attribute with Object type or Nested table?

Question

I have been creating lot many threads around the same problem, however i thought i knew but realized I do not know or else do not know how to..
I have created object type with an attribute READINGVALUE NUMBER(21,6)...How can i use type attribute on this object while declaring variable.....can we use type attribute on NESTED TABLES, similar to the db tables?
example
CREATE TYPE READING AS OBJECT(READINGVALUE NUMBER(21,6));
CREATE TABLE INTERVALREADINGS OF TYPE READING;

Answer 1

meghavee wrote:
Thanks Solomon, however this approach does not preserve precision/scale of number data type.....What you can do is create placeholder tables:
SQL> create table reading_type_placeholder of reading
  2  /
Table created.
SQL> desc reading_type_placeholder
Name                                      Null?    Type
READINGVALUE                                       NUMBER(21,6)
SQL> declare
  2      v_var reading_type_placeholder.readingvalue%type;
  3  begin
  4      v_var := 123456789012345;
  5  end;
  6  /
PL/SQL procedure successfully completed.
SQL> declare
  2      v_var reading_type_placeholder.readingvalue%type;
  3  begin
  4      v_var := 1234567890123456;
  5  end;
  6  /
declare
ERROR at line 1:
ORA-06502: PL/SQL: numeric or value error: number precision too large
ORA-06512: at line 4
SQL>And if you modify type attribute:
SQL> alter type reading modify attribute readingvalue number(26,6) cascade;
Type altered.
SQL> desc reading_type_placeholder
Name                                      Null?    Type
READINGVALUE                                       NUMBER(26,6)
SQL>SY.