[boost] Re: Serialization to relational table

From: Vladimir Prus (ghost_at_[hidden])
Date: 2002-11-18 12:43:26

Bohdan wrote:
> I believe that XML can contain any data. But i suspect that
> XML garbaged with all serialization stuff will be
>       1. unreadeable
>       2. difficult to handle automatically (by other programs).
> 
> So i was thinking about simplifying Object <-> XML serialization.
>   Recently there were talks about ditto & relational algebra libraries.
> Also there was message about stl container on disk.
> As i understand at least some of these libs require special kind
> of serialization: Object <-> Relational tuple (object-relational mapping).
> Having such mapping it would be easy to put Relational data to XML.
> And in this case XML will be very readable.

Wouldn't there be a problem with converting object with variable size?
How can you store vector<int> in a relational database? I don't see an easy way.

> I know this approach has some limitations and doesn't fit very well
> to serialization library design, but IMHO Object <-> relational tuple
> conversion would be very useful :
>     1. store/retrieve object to/from relational tables (in-memory & disk
> databases).

Do you think that automatic mapping is possible in case of relational database?

Of course, you might have Berkeley DB or something like that, which is
on disk map<string, string>. But in this case, Robert's serialization
library would work just fine. And BTW, I'd like to have such thing.

>     2. now collection of object can be represented in GUI. Ex: vector< MyObject
> 
>        can be viewed and edited by user in some kind of grid.
>     3. putting/getting relational data to/from XML is much simpler than
>        object <-> XML serialization.

Consider this code:

     class C {
     public:
            int i, j;
             struct imp;
             imp* pimp;
             vector<int> data;
     };

     vector<C> c;

How will you convert "c" into a set of tables? And will that set of tables be
easy to work with?

- Volodya