On Jun 8, 2007, at 7:01 AM, Craig L Russell wrote:
Just FYI, when JDO reads data from tables without PK, it internally
creates a unique id, similar to a generated PK, for the objects
that it reads and these ids are discarded when no longer needed.
The fact that the mapping is for tables without PK is known by the
code that creates the temporary ids.
Craig
Hi Craig,
I can probably implement this in Cayenne in about 30 minutes, as
Cayenne has a notion of "temporary id" (normally used for new
uncommitted objects). The problem of course is uniquing. So say if a
DB row is fetched from a table via a query, resulting in object A,
and then later the same row is navigated to via a relationship from
another object, resulting in a second object B, distinct from A. This
breaks the fundamental assumption about object identity. So we chose
not to go this way.
Andrus
