I generally avoid ORM's and DB to class mapping automagic as I've
found it a tad frustating when working with schema's not built by the
ORM package or when I need to do something truly bizarre or specific
only to a certian RDBMS. So I hacked this together real quick and was
wondering if anyone could see any serious problems with using this for
a user base of maybe 4-5 people to be used as a control panel and
reports system.
Using wire-shark to watch a single query transaction from a
controller, it looks like some of what SQLAlchemy does ( show
variables like ..., describe table, etc) stays resident in memory
between request cycles ( route, controller, render) so my only concern
is for SQLAlchemy handling things this way.
*ignore the credentials as I've got a proxy that handles that stuff
for me based upon which schema is requested on initial login.
#models/MultiSchema.py
import sqlalchemy as SA
from sqlalchemy.engine.url import URL
class MultiSchema(object):
schemas = {}
def addSchema(self,name,schemaURL):
self.schemas[name] = schemaURL
def __getattr__(self, attr):
if attr in self.schemas:
if type(self.schemas[attr]) == URL: #1st time calling this
schema, connect using provided URL
tempMD = SA.MetaData(self.schemas[attr])
self.schemas[attr] = MultiTable(attr,tempMD)
del(tempMD)
return self.schemas.get(attr, None)
else:
raise ValueError("There is no schema of %s" % attr)
class MultiTable(object):
def __init__(self, parent, MD):
self.parent = parent
self.MD = MD
self.tables = {}
def __getattr__(self, attr):
print "You're trying to get %s.%s!" % (self.parent,attr)
if attr not in self.tables:
self.tables[attr] = SA.Table(attr,self.MD,autoload=True)
return self.tables[attr]
commonSchemaItems = dict(
username = 'read_only',
password = ' ',
host = 'dbproxy.local',
port = '12345' #The kind of thing an idiot would have on his
luggage!
)
SchemaList = {
'cron_reports':
URL('mysql',database='cron_reports',**commonSchemaItems),
'pyrets_cove':
URL('mysql',database='pyrets_cove',**commonSchemaItems),
'enterprise':
URL('mysql',database='enterprise',**commonSchemaItems),
'idx': URL('mysql',database='idx',**commonSchemaItems),
'syslog': URL('mysql',database='syslog',**commonSchemaItems)
}
DB = MultiSchema()
for name, uri in SchemaList.iteritems():
DB.addSchema(name,uri)
######################
#Usage in controller
from multischema.models.MultiSchema import DB
#in an instancemethod
quick way
res = DB.idx.idx_master.select().limit(10).execute()
c.result = res
c.columns = res.c.keys()
#have a template render data
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"pylons-discuss" group.
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to [EMAIL PROTECTED]
For more options, visit this group at
http://groups.google.com/group/pylons-discuss?hl=en
-~----------~----~----~----~------~----~------~--~---
