import os
from sqlalchemy import create_engine
from sqlalchemy.orm import scoped_session, sessionmaker
from eventsourcing.infrastructure.datastore import Datastore, DatastoreSettings
from eventsourcing.infrastructure.sqlalchemy.records import Base
DEFAULT_SQLALCHEMY_DB_URI = 'sqlite:///:memory:'
# DEFAULT_SQLALCHEMY_DB_URI = 'sqlite:///FILE_SYSTEM_PATH'
# DEFAULT_SQLALCHEMY_DB_URI = 'mysql://username:password@localhost/eventsourcing'
# DEFAULT_SQLALCHEMY_DB_URI = 'postgresql://username:password@localhost:5432/eventsourcing'
[docs]class SQLAlchemySettings(DatastoreSettings):
def __init__(self, uri=None):
self.uri = uri or os.getenv('DB_URI', DEFAULT_SQLALCHEMY_DB_URI)
[docs]class SQLAlchemyDatastore(Datastore):
def __init__(self, base=Base, tables=None, connection_strategy='plain',
session=None, **kwargs):
super(SQLAlchemyDatastore, self).__init__(**kwargs)
self._session = session
self._engine = None
self._base = base
self._tables = tables
self._connection_strategy = connection_strategy
@property
def session(self):
if self._session is None:
if self._engine is None:
self.setup_connection()
session_factory = sessionmaker(bind=self._engine)
self._session = scoped_session(session_factory)
return self._session
[docs] def setup_connection(self):
assert isinstance(self.settings, SQLAlchemySettings), self.settings
if self._engine is None:
self._engine = create_engine(
self.settings.uri,
strategy=self._connection_strategy,
)
[docs] def setup_tables(self, tables=None):
if self._tables is not None:
for table in self._tables:
self.setup_table(table)
[docs] def setup_table(self, table):
table.__table__.create(self._engine, checkfirst=True)
[docs] def drop_tables(self):
if self._tables is not None:
for table in self._tables:
self.drop_table(table)
[docs] def drop_table(self, table):
table.__table__.drop(self._engine, checkfirst=True)
[docs] def truncate_tables(self):
self.drop_tables()
[docs] def close_connection(self):
if self._session:
self._session.close()
self._session = None
if self._engine:
self._engine = None