0.9.0

Released: February 28, 2017

• [autogenerate] [feature] The EnvironmentContext.configure.target_metadata parameter
  may now be optionally specified as a sequence of MetaData
  objects instead of a single MetaData object. The
  autogenerate process will process the sequence of MetaData
  objects in order.

  References: #38

• [bug] [commands] A CommandError is now raised when a migration file opens
  a database transaction and does not close/commit/rollback, when
  the backend database or environment options also specify transactional_ddl
  is False. When transactional_ddl is not in use, Alembic doesn't
  close any transaction so a transaction opened by a migration file
  will cause the following migrations to fail to apply.

  References: #369

• [autogenerate] [bug] [mysql] The autoincrement=True flag is now rendered within the
  Operations.alter_column() operation if the source column indicates
  that this flag should be set to True. The behavior is sensitive to
  the SQLAlchemy version in place, as the "auto" default option is new
  in SQLAlchemy 1.1. When the source column indicates autoincrement
  as True or "auto", the flag will render as True if the original column
  contextually indicates that it should have "autoincrement" keywords,
  and when the source column explcitly sets it to False, this is also
  rendered. The behavior is intended to preserve the AUTO_INCREMENT flag
  on MySQL as the column is fully recreated on this backend. Note that this
  flag does not support alteration of a column's "autoincrement" status,
  as this is not portable across backends.

  References: #413

• [bug] [postgresql] Fixed bug where Postgresql JSON/JSONB types rendered on SQLAlchemy
  1.1 would render the "astext_type" argument which defaults to
  the Text() type without the module prefix, similarly to the
  issue with ARRAY fixed in #85.

  References: #411

• [bug] [postgresql] Fixed bug where Postgresql ARRAY type would not render the import prefix
  for the inner type; additionally, user-defined renderers take place
  for the inner type as well as the outer type. Pull request courtesy
  Paul Brackin.

  References: #85

• [autogenerate] [feature] Added a keyword argument process_revision_directives to the
  command.revision() API call. This function acts in the
  same role as the environment-level
  EnvironmentContext.configure.process_revision_directives,
  and allows API use of the
  command to drop in an ad-hoc directive process function. This
  function can be used among other things to place a complete
  MigrationScript structure in place.

• [feature] [postgresql] Added support for Postgresql EXCLUDE constraints, including the
  operation directive Operations.create_exclude_constraints()
  as well as autogenerate render support for the ExcludeConstraint
  object as present in a Table. Autogenerate detection for an EXCLUDE
  constraint added or removed to/from an existing table is not
  implemented as the SQLAlchemy Postgresql dialect does not yet support
  reflection of EXCLUDE constraints.

  Additionally, unknown constraint types now warn when
  encountered within an autogenerate action rather than raise.

  References: #412

• [bug] [operations] Fixed bug in ops.create_foreign_key() where the internal table
  representation would not be created properly if the foriegn key referred
  to a table in a different schema of the same name. Pull request
  courtesy Konstantin Lebedev.