| from __future__ import with_statement |
| |
| import logging |
| from logging.config import fileConfig |
| |
| from alembic import context |
| from flask_appbuilder import Base |
| from sqlalchemy import engine_from_config, pool |
| |
| # 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 |
| from flask import current_app |
| config.set_main_option('sqlalchemy.url', |
| current_app.config.get('SQLALCHEMY_DATABASE_URI')) |
| target_metadata = Base.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.readthedocs.org/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() |
| kwargs = {} |
| if engine.name in ('sqlite', 'mysql'): |
| kwargs = { |
| 'transaction_per_migration': True, |
| 'transactional_ddl': True, |
| } |
| configure_args = current_app.extensions['migrate'].configure_args |
| if configure_args: |
| kwargs.update(configure_args) |
| |
| context.configure(connection=connection, |
| target_metadata=target_metadata, |
| #compare_type=True, |
| process_revision_directives=process_revision_directives, |
| **kwargs) |
| |
| try: |
| with context.begin_transaction(): |
| context.run_migrations() |
| finally: |
| connection.close() |
| |
| if context.is_offline_mode(): |
| run_migrations_offline() |
| else: |
| run_migrations_online() |