Annnnd, one more try: existing_creator = DBSession.query(Creator).filter_by(name=creator).first()
-- Tim Van Steenburgh On Monday, August 12, 2013 at 9:50 PM, Tim Van Steenburgh wrote: > Sorry, that should have been: > > existing_creator = > DBSession(Creator).query.filter_by(creator=creator).first() > > > On Monday, August 12, 2013 at 9:49 PM, Tim Van Steenburgh wrote: > > > It's not the append that's causing the error, it's the fact that you're > > creating a new Creator() instance, which ultimately results in an INSERT > > statement being issued. > > > > You want to append a Creator instance to `company.creator`, but you don't > > necessarily want to make a new Creator every time you instantiate a > > Company. If a Creator with the given name already exists, you'll want use > > that instead. > > > > So, roughly: > > > > class Company(Base): > > __tablename__ = "companies" > > id = Column(Integer, primary_key = True) > > company = Column(String(100), unique=True, nullable=False) > > creator = relationship("Creator", backref="companies", cascade="all") > > def __init__(self, company, creator): > > self.company = company > > existing_creator = > > DBSession(Creator).query.filter_by(name=creator).first() > > self.creator.append(existing_creator or Creator(creator)) > > > > > > -- > > Tim Van Steenburgh > > > > > > > > On Monday, August 12, 2013 at 9:41 PM, csdr...@gmail.com > > (mailto:csdr...@gmail.com) wrote: > > > > > Sorry I don't understand what you're trying to say. > > > > > > If the Creator already exists, and I'm to append it again, isn't that the > > > same as what my code is currently doing? (That is, appending in every > > > instance.) I don't see how this wouldn't result in the same error message. > > > > > > And what would it mean to create a new one and append that? I don't know > > > what this code would look like. > > > > > > Apologies if I'm being dense. > > > > > > On Monday, August 12, 2013 9:33:31 PM UTC-4, Tim wrote: > > > > In `Company.__init__()`, instead of blindly creating a new `Creator` > > > > instance, you need to first query for an existing Creator with that > > > > name. If it exists, append it, otherwise, create a new one and append > > > > that. > > > > > > > > -- > > > > Tim Van Steenburgh > > > > > > > > > > > > On Monday, August 12, 2013 at 9:26 PM, csd...@gmail.com (javascript:) > > > > wrote: > > > > > > > > > I have another question about a piece of code that I posted the other > > > > > day. Namely, I have a one-to-many relationship between Creator and > > > > > Company. A Creator can have a relationship with multiple Companies > > > > > but any one Company can have a relationship with only one Creator. > > > > > > > > > > class Company(Base): > > > > > __tablename__ = "companies" > > > > > id = Column(Integer, primary_key = True) > > > > > company = Column(String(100), unique=True, nullable=False) > > > > > creator = relationship("Creator", backref="companies", > > > > > cascade="all") > > > > > > > > > > > > > > > def __init__(self, company, creator): > > > > > self.company = company > > > > > self.creator.append(Creator(creator)) > > > > > > > > > > class Creator(Base): > > > > > __tablename__ = "creators" > > > > > > > > > > company_id = Column(Integer, ForeignKey('companies.id > > > > > (http://companies.id/)')) > > > > > creator = Column(String(100), nullable=False, unique=True) > > > > > > > > > > def __init__(self, creator): > > > > > self.creator = creator > > > > > > > > > > > > > > > So, to create a Company, the code calls company = Company(<company > > > > > name>, <creator name>) and that in turn calls Creator(). > > > > > > > > > > The problem is that the Companies get added one by one, and if a new > > > > > company being entered has a Creator with a name of a preexisting > > > > > company, SQLalchemy errors due to the unique=True flag: > > > > > > > > > > sqlalchemy.exc.IntegrityError: (IntegrityError) (1062, "Duplicate > > > > > entry 'Viking' for key 'creator'") 'INSERT INTO creators (company_id, > > > > > creator) VALUES (%s, %s)' (17L, u'Viking') > > > > > > > > > > If unique=True isn't enabled, it will create another Creator of the > > > > > same name. Instead, the code should reflect the additional Company > > > > > assigned to this particular Creator. How might I go about fixing this? > > > > > > > > > > Thanks! > > > > > > > > > > -- > > > > > You received this message because you are subscribed to the Google > > > > > Groups "sqlalchemy" group. > > > > > To unsubscribe from this group and stop receiving emails from it, > > > > > send an email to sqlalchemy+...@googlegroups.com (javascript:). > > > > > To post to this group, send email to sqlal...@googlegroups.com > > > > > (javascript:). > > > > > Visit this group at http://groups.google.com/group/sqlalchemy. > > > > > For more options, visit https://groups.google.com/groups/opt_out. > > > > > > > > > > > > > > > > > -- > > > You received this message because you are subscribed to the Google Groups > > > "sqlalchemy" group. > > > To unsubscribe from this group and stop receiving emails from it, send an > > > email to sqlalchemy+unsubscr...@googlegroups.com > > > (mailto:sqlalchemy+unsubscr...@googlegroups.com). > > > To post to this group, send email to sqlalchemy@googlegroups.com > > > (mailto:sqlalchemy@googlegroups.com). > > > Visit this group at http://groups.google.com/group/sqlalchemy. > > > For more options, visit https://groups.google.com/groups/opt_out. > > > > > > > > > -- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sqlalchemy+unsubscr...@googlegroups.com. To post to this group, send email to sqlalchemy@googlegroups.com. Visit this group at http://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/groups/opt_out.