How to use MAP and ORDER for comparison in PL/SQL?

Dear everybody

I'm learning PL/SQL of Oracle8. The MAP and ORDER methods that used for comparison confused me a lot. :-( I created a type that has one map function, but I have no idea how to use it? Can anybody give me an example of how to use it? And I read from the book that for the MAP method, it's well-suited for aggregate operations such as GROUP BY and ORDER BY. Can you show me about that?

• Specification part create or replace type Complex_numb as object (
• Here is the attributes rpart real, -- Real part ipart real, -- Imaginary part
• Here is the methods member function plus (x Complex_numb) return Complex_numb, member function minuss (x Complex_numb) return Complex_numb, map member function magnitude return real );
• Body part create or replace type body Complex_numb as member function plus (x Complex_numb) return Complex_numb is begin return Complex_numb(rpart + x.rpart, ipart + x.ipart); end plus;

   member function minuss (x Complex_numb) return Complex_numb is    begin

      return Complex_numb(rpart - x.rpart, ipart - x.ipart);    end minuss;

   map member function magnitude return real is    begin

      return(sqrt((rpart*rpart)+(ipart*ipart)));    end magnitude;
end;

Thank you in advance
Pak

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Before you buy. Received on Sun Jan 02 2000 - 21:56:07 CST