[odb-users] querying object and loading into a stack variable, then setting its id to 0 and persisting

[Boris Kolpackov]

MM <finjulhich at gmail.com> writes:

> struct C {
>   std::uint64_t id;   #pragma member id auto
>  ....
> };
> 
> C myc;
> db.query_one<future>(..., myc);
> /// successful
> myc.setid(0);
> myc.changeotherattributes();
> 
> db.persist(myc);
> 
> /// this seems to INSERT a new object with value 0 for id, but my intention
> is to clone the loaded object myc, change attributes, and let the database
> determine the new id.

Provided the C::id member is auto-assigned, this should do what you expect
so I suspect there is something wrong with your setup. If you think this is
a bug in ODB, please provide a complete reproducer and also specify which
database we are talking about. In fact, ALWAYS specify which database we
are talking about.


> does odb keep track of the object memory addresses for determining whether
> to UPDATE vs INSERT?

No, ODB doesn't do anything like this.