Using ORDER method:

An ORDER method is used to compare the object values and return values like as 1 denotes in which the current object is greater than the parameter, 0 denotes equality and -1 if the current object is less than the argument.

Note: When Member Functions are used their requirement to be specified a Restrict_References require to be specified.

Either an MAP or ORDER function alone needs to be specified.

The Object Types holds 2 parts like packages namely Specification and Body. A body is a must only when any member function is specified.

If an object type is established without any member function comparison cannot be performed as the following instance described:

select empno,ename,a.sal from emptab a;

EMPNO ENAME

--------- --------------------

SAL(BASIC, DA)

------------------------------

1 hema

SALTYPE(1000, 2300)

2 magesh

SALTYPE(10000, 20000

select a.empno,a.ename,a.sal from emptab a, emptab b

where a.sal >=b.sal;

where a.sal >=b.sal

*

ERROR at line 2:

ORA-22950:  cannot  ORDER  objects  without  ORDER  or MAP    method  Additionally  to  do  this operation write a function known as compare that compares the two objects.

CREATE OR REPLACE TYPE dep_type AS Object

(deptno number,dname varchar2(20)

Order Member Function compare (dtype In dep_type) Return Number);

Create or replace type body dep_type as order member function compare (dtype in dep_type) return number is if self.deptno > dtype.deptno then it will return 1;

else

end if;

end;

return 0;

This permits the above query to be executed.