def create_session_factory(self, **kwargs) -> "DBManager":
"""
Args:
kwargs => passed to SQLAlchemy sessionmaker constructor
Description:
Create SQLAlchemy scoped_session if self._scoped_sessions is True,
otherwise sessionmaker. All kwargs are passed to sessionmaker constructor.
This method should only be called _once_ by the DBManager. SQLAlchemy doesn't
recommend manually closing all sessions, and the mechanics for doing so have changed
across versions.
See: https://docs.sqlalchemy.org/en/13/orm/session_api.html#session-and-sessionmaker
and https://docs.sqlalchemy.org/en/13/orm/contextual.html#sqlalchemy.orm.scoping.scoped_session
and https://docs.sqlalchemy.org/en/13/orm/session_api.html#sqlalchemy.orm.session.sessionmaker.close_all
Preconditions:
N/A
Raises:
RuntimeError: if self._session_factory is already defined, or
if self._engine isn't defined
"""
# Ensure self._session_factory isn't already defined
if self._session_factory:
raise RuntimeError("Session factory already created")
# Ensure self._engine is defined
if not self._engine:
raise RuntimeError("Cannot create session factory without an Engine")
# Generate sessionmaker session factory
self._session_factory = SessionMaker(bind=self._engine, **kwargs)
# If scoped sessions, wrap in scoped_sessions factory
if self._scoped_sessions:
self._session_factory = ScopedSession(self._session_factory)
return self
def _init_session_maker():
global _session_maker
_session_maker = SessionMaker(bind=get_engine())
import os
import psycopg2
from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker as SessionMaker
#from config import DatabaseConfig
engine = create_engine(os.environ['DATABASE_URL'], echo=True)
session_maker = SessionMaker(bind=engine)
def connect_db():
db_conf = DatabaseConfig()
return psycopg2.connect(host=db_conf.db_host,
database=db_conf.db_name,
user=db_conf.db_user,
password=db_conf.db_password)
def made_sql(db_con, sql) -> bool:
try:
with db_con:
with db_con.cursor() as curs:
curs.execute(sql)
return True
except psycopg2.Error:
return False
def create_schema(db_con, sch_name):
return made_sql(db_con, 'CREATE SCHEMA {};'.format(sch_name))
def setup_sessionmaker() -> SessionMaker:
engine = create_engine(MYSQL_URL, pool_recycle=300, pool_size=10)
sessionmaker = SessionMaker(bind=engine)
return sessionmaker