here's the issue: https://bitbucket.org/zzzeek/alembic/issues/515/system-true-not-generated-for-column
and here is a patch to resolve: https://gerrit.sqlalchemy.org/#/c/zzzeek/alembic/+/910 On Wed, Oct 31, 2018 at 11:49 AM Riccardo Magliocchetti <riccardo.magliocche...@gmail.com> wrote: > > Il 31/10/18 16:32, Mike Bayer ha scritto: > > On Wed, Oct 31, 2018 at 11:00 AM Riccardo Magliocchetti > > <riccardo.magliocche...@gmail.com> wrote: > >> > >> Hello, > >> > >> we'd like to use Postgresql xmin column for optimistic concurrency, so we > >> declared the column as: > >> > >> xmin = Column("xmin", Integer, system=True, > >> server_default=FetchedValue()) > >> > >> > >> The problem is when autogenerating a migration with alembic (via > >> flask-migrate) the xmin column is added to > >> the operations so the migrations fails. > > > > is the column generated inside the migration including the > > "system=True" flag? if that flag is present then the column won't be > > created. Or are you referring to an alter table operation? Need > > specifics on the failure and then we need to post a bug report if > > there is in fact a problem. > > It's a create table, the flag is not there: > > op.create_table('user', > ... > sa.Column('xmin', sa.Integer(), server_default=FetchedValue(), > nullable=True), > > > > -- > Riccardo Magliocchetti > @rmistaken > > http://menodizero.it > > -- > You received this message because you are subscribed to the Google Groups > "sqlalchemy-alembic" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to sqlalchemy-alembic+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "sqlalchemy-alembic" group. To unsubscribe from this group and stop receiving emails from it, send an email to sqlalchemy-alembic+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
