91 lines
2.9 KiB
Python
91 lines
2.9 KiB
Python
from __future__ import with_statement
|
|
from alembic import context
|
|
from sqlalchemy import engine_from_config, pool
|
|
from logging.config import fileConfig
|
|
import logging
|
|
|
|
# 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')
|
|
|
|
# add your model's MetaData object here
|
|
# for 'autogenerate' support
|
|
# from myapp import mymodel
|
|
# target_metadata = mymodel.Base.metadata
|
|
from flask import current_app
|
|
config.set_main_option('sqlalchemy.url',
|
|
current_app.config.get('SQLALCHEMY_DATABASE_URI'))
|
|
target_metadata = current_app.extensions['migrate'].db.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.
|
|
|
|
"""
|
|
url = config.get_main_option("sqlalchemy.url")
|
|
context.configure(url=url)
|
|
|
|
with context.begin_transaction():
|
|
context.run_migrations()
|
|
|
|
|
|
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.
|
|
|
|
"""
|
|
|
|
# this callback is used to prevent an auto-migration from being generated
|
|
# when there are no changes to the schema
|
|
# reference: http://alembic.zzzcomputing.com/en/latest/cookbook.html
|
|
def process_revision_directives(context, revision, directives):
|
|
if getattr(config.cmd_opts, 'autogenerate', False):
|
|
script = directives[0]
|
|
if script.upgrade_ops.is_empty():
|
|
directives[:] = []
|
|
logger.info('No changes in schema detected.')
|
|
|
|
engine = engine_from_config(config.get_section(config.config_ini_section),
|
|
prefix='sqlalchemy.',
|
|
poolclass=pool.NullPool)
|
|
|
|
connection = engine.connect()
|
|
context.configure(connection=connection,
|
|
target_metadata=target_metadata,
|
|
process_revision_directives=process_revision_directives,
|
|
**current_app.extensions['migrate'].configure_args)
|
|
|
|
try:
|
|
with context.begin_transaction():
|
|
context.run_migrations()
|
|
except Exception as exception:
|
|
logger.error(exception)
|
|
raise exception
|
|
finally:
|
|
connection.close()
|
|
|
|
if context.is_offline_mode():
|
|
run_migrations_offline()
|
|
else:
|
|
run_migrations_online()
|