-from sqlalchemy import create_engine
+from types import StringTypes
+from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker
-Session=sessionmaker ()
-session=Session(bind=engine)
-#session.configure(bind=engine)
-from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy import Column, Integer, String
-from sqlalchemy.orm import relationship, backref
from sqlalchemy import ForeignKey
-from sfa.util.sfalogger import logger
+from sfa.util.sfalogging import logger
-Base=declarative_base()
+# this module is designed to be loaded when the configured db server is reachable
+# OTOH model can be loaded from anywhere including the client-side
-class DB:
+class Alchemy:
def __init__ (self, config):
dbname="sfa"
# will be created lazily on-demand
- self.session = None
+ self._session = None
# the former PostgreSQL.py used the psycopg2 directly and was doing
#self.connection.set_client_encoding("UNICODE")
# it's unclear how to achieve this in sqlalchemy, nor if it's needed at all
# we indeed have /var/lib/pgsql/data/postgresql.conf where
# this setting is unset, it might be an angle to tweak that if need be
# try a unix socket first - omitting the hostname does the trick
- unix_desc = "postgresql+psycopg2://%s:%s@:%s/%s"%\
+ unix_url = "postgresql+psycopg2://%s:%s@:%s/%s"%\
(config.SFA_DB_USER,config.SFA_DB_PASSWORD,config.SFA_DB_PORT,dbname)
# the TCP fallback method
- tcp_desc = "postgresql+psycopg2://%s:%s@%s:%s/%s"%\
+ tcp_url = "postgresql+psycopg2://%s:%s@%s:%s/%s"%\
(config.SFA_DB_USER,config.SFA_DB_PASSWORD,config.SFA_DB_HOST,config.SFA_DB_PORT,dbname)
- for desc in [ unix_desc, tcp_desc ] :
+ for url in [ unix_url, tcp_url ] :
try:
- self.engine = create_engine (engine_desc)
+ logger.debug("Trying db URL %s"%url)
+ self.engine = create_engine (url)
self.check()
+ self.url=url
return
except:
pass
self.engine=None
- raise Exception,"Could not connect to database"
-
+ raise Exception,"Could not connect to database %s as %s with psycopg2"%(dbname,config.SFA_DB_USER)
+
# expects boolean True: debug is ON or False: debug is OFF
def debug (self, echo):
def check (self):
self.engine.execute ("select 1").scalar()
- # create schema
- def create_schema (self):
- return Base.metadata.create_all(self.engine)
-
- # does a complete wipe of the schema, use with care
- def drop_schema (self):
- return Base.metadata.drop_all(self.engine)
-
def session (self):
if self._session is None:
Session=sessionmaker ()
self._session.close()
self._session=None
- def commit (self):
- self.session().commit()
-
- def insert (self, stuff, commit=False):
- if isinstance (stuff,list):
- self.session().add_all(stuff)
- else:
- self.session().add(obj)
+####################
+from sfa.util.config import Config
- # for compat with the previous PostgreSQL stuff
- def update (self, record):
- self.commit()
+alchemy=Alchemy (Config())
+engine=alchemy.engine
+dbsession=alchemy.session()
- def remove (self, record):
- del record
- self.commit()