[sqlalchemy] Mapping serial(auto increment) Postgres to bigserial
How does one specify that the auto incrementing field should map to big serial and not serial? thanks --~--~-~--~~~---~--~~ 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: one-to-many access and modification
-Original Message-
From: sqlalchemy@googlegroups.com
[mailto:[EMAIL PROTECTED] On Behalf Of Ken Pierce
Sent: 29 September 2007 00:21
To: sqlalchemy
Subject: [sqlalchemy] one-to-many access and modification
Hello all,
I just got into using sqlalchemy today and I have a question about
accessing data in a one-to-many relationship.
I've got a simplified example below. Basically the system is for a
group of us voting on DVDs we want to rent. There are users and films
and for each film a user makes a yes / no choice (where ? is
undecided).
# create tables
users_table = Table('users', metadata,
Column('id', Integer, primary_key=True),
Column('name', String(40)),
mysql_engine='InnodB')
films_table = Table('films', metadata,
Column('fid', Integer, primary_key=True),
Column('title', String(128)),
mysql_engine='InnodB')
choices_table = Table('choices', metadata,
Column('fid', Integer, ForeignKey('films.fid'), primary_key=True),
Column('id', Integer, ForeignKey('users.id'), primary_key=True),
Column('choice', MSEnum('?','Y','N')),
mysql_engine='InnodB')
# classes here
class User(object):
...
class Film(object):
class Choice(object):
# mappers
mapper(User, users_table)
mapper(Film, films_table, properties={'choices':relation(Choice)})
mapper(Choice, choices_table)
So, if I retrieve a Film object f, f.choices gives me a list of Choice
objects. From that Film object, I want to look up (and possibly
modify) a users choice.
My question is, is there a way to set up this relationship so that I
could access a users choice like a dictionary (either with a user id
or User object), or do I have to write a method to search the list and
return the object -- in which case, would the changes be reflected in
the session / database?
Thanks in advance,
Most impressed so far,
Ken Pierce.
You may be interested in the 'Custom List Classes' section of the
documentation:
http://www.sqlalchemy.org/docs/03/adv_datamapping.html#advdatamapping_p
roperties_customlist
If you are using 0.4, the mechanism has changed slightly:
http://www.sqlalchemy.org/docs/04/mappers.html#advdatamapping_relation_
collections
Regardless of whether you do this or not, if you wrote a method that
searched the list of choices and returned the appropriate one, the
changes should always be reflected in the session.
Hope that helps,
Simon
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[sqlalchemy] Re: IntegrityError during query?
Hi Michael, sorry about the lack of information; I wasn't clear on
what you were looking for.
The failing constraint is a customer one for email addresses:
CREATE DOMAIN base.email as TEXT CHECK
(VALUE ~ '[EMAIL PROTECTED](\\.[-\\w]+)*\\.\\w{2,4}$');
Thanks again!
Mark
On Oct 1, 5:46 pm, Michael Bayer [EMAIL PROTECTED] wrote:
On Oct 1, 2007, at 2:29 PM, [EMAIL PROTECTED] wrote:
Hi Michael,
I'm creating the session by:
Session = sessionmaker(bind = engine,
autoflush = True,
transactional = True)
session = Session()
and I'm not using any threading at all (therefore no thread-local
storage). The only thing between the commit and the next query is some
reporting of statistics (using sys.stdout).
I'm getting a constraint violation IntegrityError.
unique constraint ? PK constraint ? foreign key constraint ?are
you doing any explicit INSERT statements of your own independent of
the session ?
I cant diagnose the problem any further on this end without an
explicit example.
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[sqlalchemy] Re: Mapping serial(auto increment) Postgres to bigserial
On Oct 2, 10:06 am, voltron [EMAIL PROTECTED] wrote: How does one specify that the auto incrementing field should map to big serial and not serial? Use the sqlalchemy.databases.postgres.PGBigInteger datatype for that field. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups sqlalchemy group. To post to this group, send email to sqlalchemy@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en -~--~~~~--~~--~--~---
[sqlalchemy] Re: IntegrityError during query?
On Oct 2, 2007, at 7:56 AM, [EMAIL PROTECTED] wrote:
Hi Michael, sorry about the lack of information; I wasn't clear on
what you were looking for.
The failing constraint is a customer one for email addresses:
CREATE DOMAIN base.email as TEXT CHECK
(VALUE ~ '[EMAIL PROTECTED](\\.[-\\w]+)*\\.\\w{2,4}$');
you'd have to ensure the text youre inserting meets that regular
expression.
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[sqlalchemy] Re: IntegrityError during query?
On Oct 2, 2007, at 7:56 AM, [EMAIL PROTECTED] wrote:
Hi Michael, sorry about the lack of information; I wasn't clear on
what you were looking for.
The failing constraint is a customer one for email addresses:
CREATE DOMAIN base.email as TEXT CHECK
(VALUE ~ '[EMAIL PROTECTED](\\.[-\\w]+)*\\.\\w{2,4}$');
oh. also, you should not save() the object which represents this
insert (or at least perform any additional queries) until its fields
are fully assembled. since you are using autoflush=True, the
contents of the session will be flushed automatically before every
query.
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[sqlalchemy] Re: Multiple database connections - Using ORM to copy table data from one DB to another
I had originally tried the expunge method, as in the code I had attached, but if I just use session.save(policy), I get the aforementioned exception, and if I use session.save_or_update(policy) it simply does nothing. When using session.merge(policy), I get the following exception: File build\bdist.win32\egg\sqlalchemy\orm\session.py, line 483, in merge NameError: global name 'mapperutil' is not defined Regarding the eager-loading, I understand that the configuration of the mappers will be in effect. I meant to inquire as to whether there was a way to recursively override the mappers, as this is a different use than the ORM was originally intended for, and the usual behavior of lazy-loading is not desired here. I considered using the eagerload option, but my ORM has several levels (eg, Policy contains Insureds which each contain Addresses) and it didn't seem like the option would apply all the way down. -Original Message- From: sqlalchemy@googlegroups.com [mailto:[EMAIL PROTECTED] Behalf Of Michael Bayer Sent: Saturday, September 22, 2007 11:11 AM To: sqlalchemy@googlegroups.com Subject: [sqlalchemy] Re: Multiple database connections - Using ORM to copy table data from one DB to another On Sep 18, 2007, at 5:47 PM, Cory Johns wrote: I'm trying to make a small utility that uses a larger application's ORM to copy an object from one database (dev) to another (qa) for testing purposes. But I'm running in to trouble getting SQLAlchemy to use the multiple database connections. I can get the object to load, and then open a connection to the other database, but when I try to call save, I get the following error: sqlalchemy.exceptions.InvalidRequestError: Instance 'thig.base.model.policy.Policy object at 0x018C5AB0' is a detached instance or is already persistent in a different Session Is it possible to re-attach an ORM instance to a new session in order to duplicate the data to another database like I'm doing? If so, how do I go about that? use session.merge() is probably the most straightforward way (returns a second object instance associated with the new session). or, you can expunge() the object from the first session, then save_or_update () to the second session. Additionally, as I suspect this will be a problem once I get it re- attached, is there an easy way to specify that all properties, recursively, should be eager loaded? whatever the configuration is of the mappers() representing the involved classes will remain in effect. CONFIDENTIAL NOTICE: This email including any attachments, contains confidential information belonging to the sender. It may also be privileged or otherwise protected by work product immunity or other legal rules. This information is intended only for the use of the individual or entity named above. If you are not the intended recipient, you are hereby notified that any disclosure, copying, distribution or the taking of any action in reliance on the contents of this emailed information is strictly prohibited. If you have received this email in error, please immediately notify us by reply email of the error and then delete this email immediately. --~--~-~--~~~---~--~~ 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: Multiple database connections - Using ORM to copy table data from one DB to another
On Oct 2, 2007, at 10:32 AM, Cory Johns wrote:
I had originally tried the expunge method, as in the code I had
attached,
but if I just use session.save(policy), I get the aforementioned
exception,
and if I use session.save_or_update(policy) it simply does nothing.
When using session.merge(policy), I get the following exception:
File build\bdist.win32\egg\sqlalchemy\orm\session.py, line 483,
in merge
NameError: global name 'mapperutil' is not defined
thats a bug in the exception throw. if you upgrade to 0.4 or the
latest trunk of 0.3 its fixed (I recommend 0.4). the error message
it would like to show you is:
Instance %s has an instance key but is not persisted
which means, you are artifically attaching an _instance_key to the
object but its not actually present in the database. if youre
copying over to a new database, remove the _instance_key attribute
from the object before merging it or saving to the new session;
otherwise it thinks no changes are needed.
Regarding the eager-loading, I understand that the configuration of
the
mappers will be in effect. I meant to inquire as to whether there
was a way
to recursively override the mappers, as this is a different use
than the ORM
was originally intended for, and the usual behavior of lazy-loading
is not
desired here. I considered using the eagerload option, but my ORM has
several levels (eg, Policy contains Insureds which each contain
Addresses)
and it didn't seem like the option would apply all the way down.
the eagerload options do apply to multiple levels.in 0.3 you need
to specify a separate eagerload() option for each path, i.e.
query.options(eagerload('a'), eagerload('a.b'), eagerload('a.b.c'))
in 0.4 just use query.options(eagerload_all('a.b.c'))
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[sqlalchemy] Re: Mapping serial(auto increment) Postgres to bigserial
Thanks On Oct 2, 3:54 pm, Ants Aasma [EMAIL PROTECTED] wrote: On Oct 2, 10:06 am, voltron [EMAIL PROTECTED] wrote: How does one specify that the auto incrementing field should map to big serial and not serial? Use the sqlalchemy.databases.postgres.PGBigInteger datatype for that field. --~--~-~--~~~---~--~~ 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] Fwd: Migrate: svndump loaded into google code project
I thought this might be of interest to many of you. We've been trying to gather up a few people to and revive the floundering SQLAlchemy migrations project. There's actually some pretty good code there already, it just needs a bit of love and tenderness to get it up to date wth SQLALchemy 0.4. It would be a huge benefit to have a clear story to tell in the python world about how to do agile database development, or just how to manage database upgrades as your application evolves. If you feel up to it, join the mailing list, ([EMAIL PROTECTED]) look over the code, ask some questions, and get involved. --Mark -- Forwarded message -- From: Mark Ramm [EMAIL PROTECTED] Date: Oct 2, 2007 11:39 AM Subject: Re: Migrate: svndump loaded into google code project? To: [EMAIL PROTECTED] I just loaded Evan's svndump into the shiny new google code repository at: http://sqlalchemy-migrate.googlecode.com/svn/ Now everything is ready to start the work on reviving migrate. Thanks Jan! Just a reminder, I think we should work on getting the monkey patch removal branch working with 0.3.10 first. I think someone may have even completed this work, if so now would be a great time to check that in. ;) Once that's done I would propose moving that branch to trunk and working on making it 0.4 ready. --Mark -- Mark Ramm-Christensen email: mark at compoundthinking dot com blog: www.compoundthinking.com/blog --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
