| 123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133 |
- from __future__ import with_statement
- from alembic import context
- from sqlalchemy import engine_from_config, pool
- from logging.config import fileConfig
- import logging
- import re
- USE_TWOPHASE = False
- # this is the Alembic Config object, which provides
- # access to the values within the .ini file in use.
- config = context.config
- # Interpret the config file for Python logging.
- # This line sets up loggers basically.
- fileConfig(config.config_file_name)
- logger = logging.getLogger('alembic.env')
- # gather section names referring to different
- # databases. These are named "engine1", "engine2"
- # in the sample .ini file.
- db_names = config.get_main_option('databases')
- # add your model's MetaData objects here
- # for 'autogenerate' support. These must be set
- # up to hold just those tables targeting a
- # particular database. table.tometadata() may be
- # helpful here in case a "copy" of
- # a MetaData is needed.
- # from myapp import mymodel
- # target_metadata = {
- # 'engine1':mymodel.metadata1,
- # 'engine2':mymodel.metadata2
- #}
- target_metadata = {}
- # other values from the config, defined by the needs of env.py,
- # can be acquired:
- # my_important_option = config.get_main_option("my_important_option")
- # ... etc.
- 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.
- """
- # for the --sql use case, run migrations for each URL into
- # individual files.
- engines = {}
- for name in re.split(r',\s*', db_names):
- engines[name] = rec = {}
- rec['url'] = context.config.get_section_option(name,
- "sqlalchemy.url")
- for name, rec in engines.items():
- logger.info("Migrating database %s" % name)
- file_ = "%s.sql" % name
- logger.info("Writing output to %s" % file_)
- with open(file_, 'w') as buffer:
- context.configure(url=rec['url'], output_buffer=buffer,
- target_metadata=target_metadata.get(name),
- literal_binds=True)
- with context.begin_transaction():
- context.run_migrations(engine_name=name)
- 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.
- """
- # for the direct-to-DB use case, start a transaction on all
- # engines, then run all migrations, then commit all transactions.
- engines = {}
- for name in re.split(r',\s*', db_names):
- engines[name] = rec = {}
- rec['engine'] = engine_from_config(
- context.config.get_section(name),
- prefix='sqlalchemy.',
- poolclass=pool.NullPool)
- for name, rec in engines.items():
- engine = rec['engine']
- rec['connection'] = conn = engine.connect()
- if USE_TWOPHASE:
- rec['transaction'] = conn.begin_twophase()
- else:
- rec['transaction'] = conn.begin()
- try:
- for name, rec in engines.items():
- logger.info("Migrating database %s" % name)
- context.configure(
- connection=rec['connection'],
- upgrade_token="%s_upgrades" % name,
- downgrade_token="%s_downgrades" % name,
- target_metadata=target_metadata.get(name)
- )
- context.run_migrations(engine_name=name)
- if USE_TWOPHASE:
- for rec in engines.values():
- rec['transaction'].prepare()
- for rec in engines.values():
- rec['transaction'].commit()
- except:
- for rec in engines.values():
- rec['transaction'].rollback()
- raise
- finally:
- for rec in engines.values():
- rec['connection'].close()
- if context.is_offline_mode():
- run_migrations_offline()
- else:
- run_migrations_online()
|
