codekingpro/portable-devtools

1import logging2from logging.config import fileConfig3import re4 5from sqlalchemy import engine_from_config6from sqlalchemy import pool7 8from alembic import context9 10USE_TWOPHASE = False11 12# this is the Alembic Config object, which provides13# access to the values within the .ini file in use.14config = context.config15 16# Interpret the config file for Python logging.17# This line sets up loggers basically.18if config.config_file_name is not None:19    fileConfig(config.config_file_name)20logger = logging.getLogger("alembic.env")21 22# gather section names referring to different23# databases.  These are named "engine1", "engine2"24# in the sample .ini file.25db_names = config.get_main_option("databases", "")26 27# add your model's MetaData objects here28# for 'autogenerate' support.  These must be set29# up to hold just those tables targeting a30# particular database. table.tometadata() may be31# helpful here in case a "copy" of32# a MetaData is needed.33# from myapp import mymodel34# target_metadata = {35#       'engine1':mymodel.metadata1,36#       'engine2':mymodel.metadata237# }38target_metadata = {}39 40# other values from the config, defined by the needs of env.py,41# can be acquired:42# my_important_option = config.get_main_option("my_important_option")43# ... etc.44 45 46def run_migrations_offline() -> None:47    """Run migrations in 'offline' mode.48 49    This configures the context with just a URL50    and not an Engine, though an Engine is acceptable51    here as well.  By skipping the Engine creation52    we don't even need a DBAPI to be available.53 54    Calls to context.execute() here emit the given string to the55    script output.56 57    """58    # for the --sql use case, run migrations for each URL into59    # individual files.60 61    engines = {}62    for name in re.split(r",\s*", db_names):63        engines[name] = rec = {}64        rec["url"] = context.config.get_section_option(name, "sqlalchemy.url")65 66    for name, rec in engines.items():67        logger.info("Migrating database %s" % name)68        file_ = "%s.sql" % name69        logger.info("Writing output to %s" % file_)70        with open(file_, "w") as buffer:71            context.configure(72                url=rec["url"],73                output_buffer=buffer,74                target_metadata=target_metadata.get(name),75                literal_binds=True,76                dialect_opts={"paramstyle": "named"},77            )78            with context.begin_transaction():79                context.run_migrations(engine_name=name)80 81 82def run_migrations_online() -> None:83    """Run migrations in 'online' mode.84 85    In this scenario we need to create an Engine86    and associate a connection with the context.87 88    """89 90    # for the direct-to-DB use case, start a transaction on all91    # engines, then run all migrations, then commit all transactions.92 93    engines = {}94    for name in re.split(r",\s*", db_names):95        engines[name] = rec = {}96        rec["engine"] = engine_from_config(97            context.config.get_section(name, {}),98            prefix="sqlalchemy.",99            poolclass=pool.NullPool,100        )101 102    for name, rec in engines.items():103        engine = rec["engine"]104        rec["connection"] = conn = engine.connect()105 106        if USE_TWOPHASE:107            rec["transaction"] = conn.begin_twophase()108        else:109            rec["transaction"] = conn.begin()110 111    try:112        for name, rec in engines.items():113            logger.info("Migrating database %s" % name)114            context.configure(115                connection=rec["connection"],116                upgrade_token="%s_upgrades" % name,117                downgrade_token="%s_downgrades" % name,118                target_metadata=target_metadata.get(name),119            )120            context.run_migrations(engine_name=name)121 122        if USE_TWOPHASE:123            for rec in engines.values():124                rec["transaction"].prepare()125 126        for rec in engines.values():127            rec["transaction"].commit()128    except:129        for rec in engines.values():130            rec["transaction"].rollback()131        raise132    finally:133        for rec in engines.values():134            rec["connection"].close()135 136 137if context.is_offline_mode():138    run_migrations_offline()139else:140    run_migrations_online()141