I keep thinking one of my relatives has emailed me when you post here and I get all excited. Any chance you can change your name ? :-)
2008/12/2 Doug Farrell <[EMAIL PROTECTED]>: > Michael, > > > > Thanks for the pointer, that makes great sense, and once again points how my > generally small database design skills. I'll update my code to try this out. > > > > Again, > > Thanks! > > Doug > > > > From: sqlalchemy@googlegroups.com [mailto:[EMAIL PROTECTED] On > Behalf Of Michael Bayer > Sent: Saturday, November 29, 2008 9:28 PM > To: sqlalchemy@googlegroups.com > Subject: [sqlalchemy] Re: New instance ExtraStat with identity key (...) > conflicts with persistent instance ExtraStat > > > > Simon's suggestion about the duplicate "name" still holds. Your relation > from Stat->ExtraStat currently needs to be one-to-one since you cannot have > more than one ExtraStat referencing a single Stat, due to the PK constraint > on ExtraStat.name. The error is raising at the point of query() since > autoflush is kicking in - use session.flush() to isolate the error. > > > > On Nov 29, 2008, at 12:18 PM, Doug Farrell wrote: > > Hi all, > > > > I'm having a problem with a new instance of a relation conflicting with > > an existing instance. I'm using SA 0.5rc with Sqlite3. Here are my > > simplified classes: > > > > class Stat(sqladb.Base): > > __tablename__ = "stats" > > name = Column(String(32), primary_key=True) > > total = Column(Integer) > > created = Column(DateTime, default=datetime.datetime.now()) > > updated = Column(DateTime) > > states = Column(PickleType, default={}) > > extraStats = relation("ExtraStat", backref="stat") > > > > class ExtraStat(sqladb.Base): > > __tablename__ = "extrastats" > > name = Column(String(32), ForeignKey("stats.name"), > primary_key=True) > > total = Column(Integer) > > created = Column(DateTime, default=datetime.datetime.now()) > > updated = Column(DateTime) > > states = Column(PickleType, default={}) > > > > The above Stat class has a one-to-many relationship with the ExtraStat > > class (which I think I've implemented correctly). Later in the > > program I create an in memory data model that has as part of it's > > components two > > dictionaries that contain Stat instances. Those Stat instances have > > relationships to ExtraStat instances. My problem comes in the > > following when I'm trying to update the data in those instances/tables. > > Here is a section of code that throws the exception: > > > > > > > > pressName = "press%s" % pressNum > > # add new ExtraStat instances as relations > > self._addProductStatsPress(productType, pressName) > > self._addPressStatsProduct(pressName, productType) > > try: > > extraStat = session.query(Stat). \ > > filter(Stat.name==productType). \ > > join("extraStats"). \ > > filter(ExtraStat.name==pressName).one() > > except: > > extraStat = ExtraStat(pressName, ExtraStat.PRESS_TYPE) > > self.productStats[productType].extraStats.append(extraStat) > > extraStat.states.setdefault(sstate, 0) > > extraStat.states[sstate] += 1 > > extraStat.updated = now > > extraStat = session.merge(extraStat) > > try: > > extraStat = session.query(Stat). \ > > filter(Stat.name==pressName). \ > > join("extraStats"). \ > > filter(ExtraStat.name==productType).one() <==== throws > exception right here > > except: > > extraStat = ExtraStat(productType, ExtraStat.PRODUCT_TYPE) > > self.pressStats[pressName].extraStats.append(extraStat) > > extraStat.states.setdefault(sstate, 0) > > extraStat.states[sstate] += 1 > > extraStat.updated = now > > > > The marked area is wear it throws the exception. I'm not sure what to > > do here to get past this, any help or ideas would be greatly > > appreciated. > > > > The exact exception is as follows: > > Sqlalchemy.orm.exc.FlushError: New instance [EMAIL PROTECTED] With identity > > key (<class '__main__.ExtraStat'>,(u'C',)) conflicts with persistent > > instance [EMAIL PROTECTED] > > > > Thanks! > > Doug > > > > > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To post to this group, send email to sqlalchemy@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en -~----------~----~----~----~------~----~------~--~---
