[odb-users] Use of data_migration_entry

[Boris Kolpackov]

Andrew Cunningham <odb at a-cunningham.com> writes:

> However, when I open a version "1" database, I get an exception as
> migrate_c () is called.
> The exception occurs, presumably, the version "1" db schema knows nothing
> about objects of class "C".

In this case the database should first be migrated from version 1 to 2
and then from 2 to 3 at which point migrate_c() should be called.

Can you print the exception being thrown as well as db.schema_version()
from inside migrate_c() and see if this sheds any light?