[odb-users] ODB Help.

[Boris Kolpackov]

Hi,

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art at it-gen.net writes:

> So we have an external rating system that counts every day rating, and
> it does not matter to us as operations rating renewed in ODB, but
> important to the previous value rating which now sits in a cache
> program, not erased numbered rating that sits in the database.
> 
> Thats why we shared an one ODB object in two objects, and imitate
> readonly follows - 2nd object only read from the database and do not
> write in database.

Ok, if I understand you correctly, you can emulate this behavior by
adding a transient "cache" member (which is not stored in the databse)
to your persistent class. For example:

#pragma db object
class post
{
public:
  post (unsigned int initial_rating)
    : rating_ (initial_rating),
      initial_rating_ (initial_rating)
  {
  }

  unsigned int 
  initial_rating () const
  {
    return initial_rating_;
  }

private:
  unsigned int rating_;
  
  #pragma db transient
  unsigned int initial_rating_;
};

Would this work for you?

Boris