env Namespace Reference

Functions
def	run_migrations_offline ()
def	run_migrations_online ()

Variables
	Base = declarative_base(metadata=meta)
	config = context.config
	logger = logging.getLogger('alembic.runtime.setup')
	meta
	below block is needed for mssql More...
	target_metadata = None

Function Documentation

run_migrations_offline()

def env.run_migrations_offline

(

)

Run migrations in 'offline' mode.

This configures the context with just a URL
and not an Engine, though an Engine is acceptable
here as well.  By skipping the Engine creation
we don't even need a DBAPI to be available.

Calls to context.execute() here emit the given string to the
script output.

Definition at line 45 of file env.py.

Referenced by run_migrations_online().

def run_migrations_offline():
    """Run migrations in 'offline' mode.

    This configures the context with just a URL
    and not an Engine, though an Engine is acceptable
    here as well.  By skipping the Engine creation
    we don't even need a DBAPI to be available.

    Calls to context.execute() here emit the given string to the
    script output.

    """
    url = config.get_main_option("sqlalchemy.url")
    context.configure(url=url,target_metadata=target_metadata)

    with context.begin_transaction():
        context.run_migrations()

run_migrations_online()

def env.run_migrations_online

(

)

Run migrations in 'online' mode.

In this scenario we need to create an Engine
and associate a connection with the context.

Definition at line 63 of file env.py.

References run_migrations_offline().

def run_migrations_online():
    """Run migrations in 'online' mode.

    In this scenario we need to create an Engine
    and associate a connection with the context.

    """
    engine = engine_from_config(
                config.get_section(config.config_ini_section),
                prefix='sqlalchemy.',
                poolclass=pool.NullPool)

    logger.info('Testing for an old alembic_version table.')

    connection = engine.connect()
    context.configure(
                connection=connection,
                target_metadata=target_metadata,
                version_table='alembic_version'
                )

    script_location = config.get_main_option('script_location')
    found = False
    mc = context.get_context()
    current_db_revision = mc.get_current_revision()
    script = ScriptDirectory.from_config(config)
    """ If there was an existing alembic_version table, we need to
    check that it's current revision is in the history for the tree
    we're working with.
    """
    for x in script.iterate_revisions('head', 'base'):
        if x.revision == current_db_revision:
            """ An alembic_versions table was found and it belongs to
            this alembic tree
            """
            logger.info(
                ('An old alembic_version table at revision %s was '
                 'found for %s.  Renaming to alembic_version_%s.'),
                        current_db_revision, script_location,
                        script_location)
            op = Operations(mc)
            try:
                with context.begin_transaction():
                    op.rename_table(
                        'alembic_version', 'alembic_version_%s'
                        % script_location)
                found = True
            except:
                logger.error(('Unable to rename alembic_version to '
                             'alembic_version_%s.'),
                             script_location)
                connection.close()
                return

            break

    if not found:
        logger.info('Didn\'t find an old alembic_version table.')
    logger.info('Trying alembic_version_%s.' % script_location)

    """ We MAY have an alembic_version table that doesn't belong to
    this tree but if we still don't have an alembic_version_<tree>
    table, alembic will create it.
    """
    context.configure(
                connection=connection,
                target_metadata=target_metadata,
                version_table='alembic_version_' + script_location
                )
    mc = context.get_context()
    current_db_revision = mc.get_current_revision()
    if current_db_revision:
        logger.info(
            'Using the alembic_version_%s table at revision %s.',
            script_location, current_db_revision)
    else:
        logger.info('Creating new alembic_version_%s table.',
                    script_location)

    try:
        with context.begin_transaction():
            context.run_migrations()
    finally:
        connection.close()

Variable Documentation

Base

Base = declarative_base(metadata=meta)

Definition at line 29 of file env.py.

config

config = context.config

Definition at line 12 of file env.py.

logger

logger = logging.getLogger('alembic.runtime.setup')

Definition at line 31 of file env.py.

meta

meta

below block is needed for mssql

Definition at line 22 of file env.py.

Referenced by nroot(), send_trunk(), and socket_process_helper().

target_metadata

target_metadata = None

Definition at line 36 of file env.py.