[odb-users] Altering column from integer to double precision

[Philip Ethier]

Alright, thanks for the reply Boris.
On Aug 16, 2014 7:18 AM, "Boris Kolpackov" <boris at codesynthesis.com> wrote:

> Hi Philip,
>
> Philip Ethier <philip.ethier at gmail.com> writes:
>
> > I was trying to use the void schema_version_migration() function to set
> > my version, but it doesn't seem to be persisting even though no
> exceptions
> > are thrown.
>
> The schema_version_migration() modifier does not persist anything. It
> simply stores the version in the odb::<db>::database instance so that
> it can be used by the generated code during the execution of the
> application. Quoting Section 12.2:
>
> "You may already have a version table in your database or you (or your
>  database administrator) may prefer to keep track of versions your own
>  way. You can instruct ODB not to create the schema_version table with the
>  --suppress-schema-version option. However, ODB still needs to know the
>  current database version in order for certain schema evolution mechanisms
> to
>  function properly. As a result, in this case, you will need to set the
> schema
>  version on the database instance manually using the
>  schema_version_migration() modifier."
>
> The version and the migration flags are only "persisted" by the pre- and
> post-schema migration scripts. Which means that if you run your own
> custom script instead, then you have to update the version as well.
>
> Boris
>