[sqlalchemy] Weird mapper() behaviour (bug?)
Hi guys! Here goes the code sample:
from sqlalchemy import create_engine, MetaData
from sqlalchemy import Table, Column, ForeignKey, Integer
from sqlalchemy.orm import sessionmaker, mapper, relation
metadata = MetaData()
engine = create_engine('sqlite:///:memory:', echo=True)
parent_table = Table('parent', metadata,
Column('id', Integer, primary_key=True))
child_table = Table('child', metadata,
Column('id', Integer, primary_key=True),
Column('parent_id', Integer, ForeignKey('parent.id')))
class Parent(object): pass
class Child(object): pass
mapper(Parent, parent_table, properties={'children': relation(Child,
backref=u'parent')})
mapper(Child, child_table)
metadata.create_all(engine)
session = sessionmaker(bind=engine)()
parentobj = Parent()
Running this code fails with this error:
.../SQLAlchemy-0.5.2-py2.6.egg/sqlalchemy/orm/properties.pyc in
_post_init(self)
993
994 if self.backref is not None:
-- 995 self.backref.compile(self)
996 elif not mapper.class_mapper(self.parent.class_,
compile=False)._get_property(self.key, raiseerr=False):
997 raise sa_exc.ArgumentError(Attempting to assign a
new relation '%s' to
AttributeError: 'unicode' object has no attribute 'compile'
This line is the problem:
mapper(Parent, parent_table, properties={'children': relation
(Child, backref=u'parent')})
or, to be precise, `backref=u'parent'`. With just `backref='parent'`,
everything works just fine, it breaks down when using a unicode
literal for backref name. Is this a bug, or somehow expected behavior?
Thanks everyone...
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[sqlalchemy] Re: Weird mapper() behaviour (bug?)
On Mar 3, 1:03 am, Michael Bayer mike...@zzzcomputing.com wrote: its a bug, there's an isinstance(str) that should be isinstance(basestring). please file a trac ticket. Done, here it is: http://www.sqlalchemy.org/trac/ticket/1330 -- Karlo Lozovina --~--~-~--~~~---~--~~ 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 sqlalchemy+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en -~--~~~~--~~--~--~---
[sqlalchemy] Properly closing all database connections
I'm using SA with SQLite, and after executing session.close() and clear_mappers(), on Linux, lsof still says my SQLite file is open. Running engine.dispose() seems to finally close it, but I'm not sure if that's the proper way? Thanks, Karlo. --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
[sqlalchemy] Re: Properly closing all database connections
On May 6, 10:53 pm, jason kirtland [EMAIL PROTECTED] wrote: That's correct. The engine holds the connection pool and dispose() will close the connections it manages. Thanks... it's weird there's no mention of it in the docs. -- Karlo Lozovina - Mosor --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
[sqlalchemy] Duplication of rows in many-to-many relationship
Let's say I have two classes A and B, and I want instances of both classes, to have a list of each other, that is, many-to-many relationship. For a shorthand, a means instance of A, and b is an instance of B. For example: a.bs is a list, full of instances of class B. Similarly, b.as is a list, full of instances of class A. In modelling that relationship I use three tables, one for As, one for Bs, and one for their relationship. If I only append instances of B to some a.bs, then save all those objects, everything works fine. But if I append instances of A and B, both to a.bs and b.as, then save, I get double rows in the third table. Is there a way around that? P.S. In a very likely case I haven't been completely understood, I'll attach some code to demonstrate my point ;). Thanks all. --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
[sqlalchemy] Re: Duplication of rows in many-to-many relationship
On May 4, 10:40 pm, Barry Hart [EMAIL PROTECTED] wrote: By chance, in your mappers, are you declaring two relationships instead of one relation with a backref? Yep, that was it, thanks! Should have read the docs more carefully ;). As a side note, once you straighten this out, you may want to declare the composite (a_id, b_id) as a unique key on the relation table. I'll look into it... Thanks for a speedy reply ;). --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
[sqlalchemy] Linking column default values?
Hi guys, sorry for the vague subject, here is my problem. Let's say I
have the following table:
a = Table('aaa', meta,
Column('id', Integer, primary_key=True),
Column('id2', Integer))
class A(object):
pass
mapper(A, a)
I want the default value of A.id2 to be that of a A.id. So, for
example, unless I modify it, I would like the A.id2 to be sort of a
duplicate primary key. I know I can find out what is A.id after
committing my object to database and then setting A.id2 accordingly,
but I was wondering can SA do this automatically for me? Maybe some
kind of a special `default=` construct in the Column call?
Thanks,
Karlo.
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[sqlalchemy] SQLite and ON CONFLICT clause?
Hi all, browsing the SQLAlchemy docs I coudn't find any references to a particular SQLite feature, ON CONFLICT clause (http://www.sqlite.org/ lang_conflict.html), is there any support for this in SA? What I want to do is this, create my database as such: CREATE TABLE songs( id INTEGER PRIMARY KEY ON CONFLICT REPLACE, name TEXT ); Now, when I do a bunch of INSERTs without specifying 'id' field, everything works as you would expect. But, when I issue a INSERT with a 'id' that allready exists, SQLite automatically and automagicaly does an UPDATE instead. Now, this is very handy because I don't have to do a SELECT prior to modifying a table. Is there a way to use this SQLite feature from SA? Or somehow simulate it without too much gory details? Thanks guys, klm. --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
[sqlalchemy] SA support for SQLite ATTACH?
Greetings everyone, does SQLAlchemy somehow support SQLites' ATTACH DATABASE statement? I have a in-memory SQLite database that I want to dump to file, so I was thinking of using ATTACH to do it. Any other ideas welcome ;). Thanks in advance, Karlo. --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
[sqlalchemy] Re: SA support for SQLite ATTACH?
On Mar 9, 4:33 pm, Michael Bayer [EMAIL PROTECTED] wrote: attach database ...wow i never knew it had that ! if its a matter of issuing the string attach database, just use literal text() or engine.execute(). Me neither ;), until the other day I started looking for an efficient way to dump in-memory SQLite databases to hdd. And this ATTACH thing sounded just like made for it. attach databasevery handy ! So, let's say I issue this engine.execute(), how would one proceede inserting rows into this attached database. Let's say mem_db is the main, in-memory database, and file_db has just been attached, and is a in-file database. SQL syntax is somewhat like this: INSERT INTO file_db.table1 SELECT * FROM mem_db.table1, is any way SQLAlchemy can do this without resorting to engine.execute() ? Thanks! Karlo. --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
