[sqlalchemy] Learn Chinese (Mandarin) faster by using flashcards with pictures
http://www.ichineseflashcards.com will help you learn Chinese (Mandarin) faster by using flashcards with pictures, 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 sqlalchemy+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en.
[sqlalchemy] What's the idiomatic way of writing INSERT... ON DUPLICATE KEY UPDATE
when using SqlAlchemy Core (not using Session/ORM)? I have quite a few tables with composite primary keys that can use it for optimization. At the moment what I have is quite ghetto, below is a contrive example of it: stmt = str(user_table.insert().values(email=email, name=name)) stmt += " ON DUPLICATE KEY UPDATE name=%s" engine.execute(stmt, email, name, name) NOTE: I believe this is MySQL specific. -- 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] expunge cascade behavior change
Somewhere between 0.6.4 and 0.7.5, the expunge cascade behavior
changed. Can you help me understand what changed/point me to the
ticket? The attached script assertions succeed in 0.6.4 but the last
one fails in 0.7.5. It doesn't seem wrong, but I'm wondering what the
behavior was defined as previously and if that was considered a bug, etc.
Thanks,
Kent
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from sqlalchemy import *
from sqlalchemy.orm import *
from sqlalchemy.orm.util import has_identity
engine = create_engine('sqlite:///', echo=True)
metadata = MetaData(engine)
Session = sessionmaker(bind=engine)
rocks_table = Table("rocks", metadata,
Column("id", Integer, primary_key=True),
)
bugs_table = Table("bugs", metadata,
Column("id", Integer, primary_key=True),
Column("rockid", Integer, ForeignKey('rocks.id'),),
)
class Rock(object):
def __repr__(self):
return '' % (id(self), self.__dict__.get('id'), self in session, has_identity(self))
class Bug(object):
def __repr__(self):
return '' % (id(self), self.__dict__.get('id'), self.__dict__.get('rockid'), self.__dict__.get('rock','not set'))
mapper(Rock, rocks_table,
properties={'bugs': relationship(Bug,
cascade='all,delete-orphan',
backref=backref('rock',cascade='refresh-expire,expunge'))
})
mapper(Bug, bugs_table)
metadata.create_all()
session = Session()
# add a rock and bug
rock=Rock()
rock.id = 0
bug=Bug()
bug.id = 0
rock.bugs.append(bug)
session.add(rock)
session.commit()
# later... new session
session = Session()
rock = session.query(Rock).get(0)
rock.bugs.append(Bug())
assert rock in session
rock.bugs = []
assert rock in session
Re: [sqlalchemy] Overload Query Object
Hi,
Have you checked the __iter__ method ?
-Original Message-
From: Christian Démolis
Sender: sqlalchemy@googlegroups.com
Date: Tue, 31 Jan 2012 17:39:54
To: sqlalchemy
Reply-To: sqlalchemy@googlegroups.com
Subject: [sqlalchemy] Overload Query Object
Hi Michael,
i overload class Query in my script.
i have 4 ways to obtain query's results.
1/ session.query(model.x).all()
2/ session.query(model.x).first()
3/ session.query(model.x).one()
4/ for e in session.query(model.x):
print e
in case 1,2,3, i know which method is used
What method is used in case 4 ?
Thanks in advance.
Chris
class Query(Query):
def __init__(self, *arg, **kw):
self._populate_existing = True
super(Query, self).__init__(*arg, **kw)
def all(self):
print "", threading.current_thread()
param.lock_bdd.acquire()
global session
try:
x = super(Query, self).all()
except exc2.OperationalError:
import common
common.alerte("L'écriture a échoué. Retentez l'action", "Erreur
MySQL")
session.rollback()
except exc2.StatementError:
import common
common.alerte("L'écriture a échoué. Retentez l'action", "Erreur
MySQL")
session.rollback()
except:
raise
param.lock_bdd.release()
print "", threading.current_thread()
return x
def one(self):
print "", threading.current_thread()
param.lock_bdd.acquire()
global session
try:
x = super(Query, self).one()
except exc2.OperationalError:
import common
common.alerte("L'écriture a échoué. Retentez l'action", "Erreur
MySQL")
session.rollback()
except exc2.StatementError:
import common
common.alerte("L'écriture a échoué. Retentez l'action", "Erreur
MySQL")
session.rollback()
except:
raise
param.lock_bdd.release()
print "", threading.current_thread()
return x
def first(self):
print "", threading.current_thread()
param.lock_bdd.acquire()
global session
try:
x = super(Query, self).first()
except exc2.OperationalError:
import common
common.alerte("L'écriture a échoué. Retentez l'action", "Erreur
MySQL")
session.rollback()
except exc2.StatementError:
import common
common.alerte("L'écriture a échoué. Retentez l'action", "Erreur
MySQL")
session.rollback()
except:
raise
param.lock_bdd.release()
print "", threading.current_thread()
return x
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[sqlalchemy] Overload Query Object
Hi Michael,
i overload class Query in my script.
i have 4 ways to obtain query's results.
1/ session.query(model.x).all()
2/ session.query(model.x).first()
3/ session.query(model.x).one()
4/ for e in session.query(model.x):
print e
in case 1,2,3, i know which method is used
What method is used in case 4 ?
Thanks in advance.
Chris
class Query(Query):
def __init__(self, *arg, **kw):
self._populate_existing = True
super(Query, self).__init__(*arg, **kw)
def all(self):
print "", threading.current_thread()
param.lock_bdd.acquire()
global session
try:
x = super(Query, self).all()
except exc2.OperationalError:
import common
common.alerte("L'écriture a échoué. Retentez l'action", "Erreur
MySQL")
session.rollback()
except exc2.StatementError:
import common
common.alerte("L'écriture a échoué. Retentez l'action", "Erreur
MySQL")
session.rollback()
except:
raise
param.lock_bdd.release()
print "", threading.current_thread()
return x
def one(self):
print "", threading.current_thread()
param.lock_bdd.acquire()
global session
try:
x = super(Query, self).one()
except exc2.OperationalError:
import common
common.alerte("L'écriture a échoué. Retentez l'action", "Erreur
MySQL")
session.rollback()
except exc2.StatementError:
import common
common.alerte("L'écriture a échoué. Retentez l'action", "Erreur
MySQL")
session.rollback()
except:
raise
param.lock_bdd.release()
print "", threading.current_thread()
return x
def first(self):
print "", threading.current_thread()
param.lock_bdd.acquire()
global session
try:
x = super(Query, self).first()
except exc2.OperationalError:
import common
common.alerte("L'écriture a échoué. Retentez l'action", "Erreur
MySQL")
session.rollback()
except exc2.StatementError:
import common
common.alerte("L'écriture a échoué. Retentez l'action", "Erreur
MySQL")
session.rollback()
except:
raise
param.lock_bdd.release()
print "", threading.current_thread()
return x
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Re: [sqlalchemy] ClassManager.new_instance does not longer initialize polymorphic column
On Jan 31, 2012, at 7:08 AM, Torsten Landschoff wrote: > On Tue, 2012-01-31 at 12:52 +0100, Torsten Landschoff wrote: > >> However, with SQLAlchemy 0.7.5 I get >> >> $ python new_instance.py >> Traceback (most recent call last): >> File "new_instance.py", line 27, in >>session.commit() >> [...] >> File >> "/usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.7.5dev-py2.6-linux-x86_64.egg/sqlalchemy/engine/default.py", >> line 330, in do_execute >>cursor.execute(statement, parameters) >> sqlalchemy.exc.IntegrityError: (IntegrityError) people.type may not be NULL >> u'INSERT INTO people (type) VALUES (?)' (None,) If you're using new_instance() to create the instance, then you are deserializing data from somewhere, why isn't the discriminator value, which is after all one of the column values in the table, not present in this deserialization ? Right now the event in question is emitted only from the __init__() method of your object, which is obviously what you don't call when deserializing.The discriminator value is now considered to be just another instance variable that you can change freely - a default for it is configured from __init__(). Anyway the event here is the "init" event which you can emit from classmanager: manager.dispatch.init(state, args, kw) where "args", "kw" are what would normally be sent to __init__, but can just be blank here. Invoking the events is not entirely public API, though. > > I found a workaround: > > --- a/new_instance.py 2012-01-31 12:50:44.510525675 +0100 > +++ b/new_instance.py 2012-01-31 13:05:52.110514861 +0100 > @@ -1,6 +1,6 @@ > from sqlalchemy import * > from sqlalchemy.orm import * > -from sqlalchemy.orm.attributes import manager_of_class > +from sqlalchemy.orm.attributes import manager_of_class, instance_state > from sqlalchemy.ext.declarative import declarative_base > > > @@ -22,7 +22,11 @@ > Base.metadata.create_all(engine) > session = sessionmaker(engine)() > > -e = manager_of_class(Engineer).new_instance() > +manager = manager_of_class(Engineer) > +e = manager.new_instance() > +state = instance_state(e) > +manager.mapper._set_polymorphic_identity(state) > + > session.add(e) > session.commit() > > But this is leaving the area of documented API. I found out that > SQLAlchemy actually initializes the polymorphic_identity column by > registering an on_init event. I'd rather trigger that but I did not yet > find out how to do that. > > Thanks, Torsten > > -- > DYNAmore Gesellschaft fuer Ingenieurdienstleistungen mbH > Torsten Landschoff > > Office Dresden > Tel: +49-(0)351-4519587 > Fax: +49-(0)351-4519561 > > mailto:torsten.landsch...@dynamore.de > http://www.dynamore.de > > Registration court: Stuttgart, HRB 733694 > Managing director: Prof. Dr. Karl Schweizerhof, Dipl.-Math. Ulrich Franz > > > -- > 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. > -- 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.
Re: [sqlalchemy] SQLAlchemy 0.7.5 Released
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 That is a bug with readthedocs. The content should be the 0.7.5 content (not 100% sure though). On Jan 31, 2012, at 2:12 AM, Fayaz Yusuf Khan wrote: > On Saturday 28 Jan 2012 6:05:51 PM Michael Bayer wrote: >> SQLAlchemy 0.7.5 is now available. > Where's the documentation (pdf)? Or has nothing changed there since 0.7.4? > http://media.readthedocs.org/pdf/sqlalchemy/latest/sqlalchemy.pdf still gives > the older pdf. > -- > Fayaz Yusuf Khan > Cloud developer and architect > Dexetra SS, Bangalore, India > fayaz.yusuf.khan_AT_gmail_DOT_com > fayaz_AT_dexetra_DOT_com > +91-9746-830-823 -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.11 (Darwin) Comment: GPGTools - http://gpgtools.org iQEcBAEBAgAGBQJPKAWVAAoJEDMCOcHE2v7hir4IAIycYUS/xzQupjHT7nygx7Z5 sYfK4MjHMZ+DMoYl6EvEYd/sPS9Zalv//El1izSUS3RypsFWgW9qQi5Cvob8fypH 53vHPCPQZSdiLBhU9VZnMT+KvepQ+3hQWjGZt+HPK71uZfCpkeIb2woPsec9ZldI X1aB9Ne806WihXe1dF8vwhmJ7B21yqufjv1kjh5/GY9luyawxq407+YXSOHYnIQP 9/w1SF37D5UxrHeekxvfjxe9jWJyT7xDr+LEGuPfb4KSKTaePCo48kFeDAPRa6kq pJ5+xKfvRPZrUawaTSE3PvWeinQDkrDQnQj2j7sH5umoka+V+hQDchvpaP3e6pY= =XS7L -END PGP SIGNATURE- -- 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] NEW and OLD objects in sqlalchemy events
I try rewrite trigger for postgresql in python sqlalchemy event function. Can I in sqlalchemy event context get NEW and OLD objects? I need compare attributes of NEW and OLD objects. 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 sqlalchemy+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en.
Re: [sqlalchemy] ClassManager.new_instance does not longer initialize polymorphic column
On Tue, 2012-01-31 at 12:52 +0100, Torsten Landschoff wrote: > However, with SQLAlchemy 0.7.5 I get > > $ python new_instance.py > Traceback (most recent call last): > File "new_instance.py", line 27, in > session.commit() > [...] > File > "/usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.7.5dev-py2.6-linux-x86_64.egg/sqlalchemy/engine/default.py", > line 330, in do_execute > cursor.execute(statement, parameters) > sqlalchemy.exc.IntegrityError: (IntegrityError) people.type may not be NULL > u'INSERT INTO people (type) VALUES (?)' (None,) I found a workaround: --- a/new_instance.py 2012-01-31 12:50:44.510525675 +0100 +++ b/new_instance.py 2012-01-31 13:05:52.110514861 +0100 @@ -1,6 +1,6 @@ from sqlalchemy import * from sqlalchemy.orm import * -from sqlalchemy.orm.attributes import manager_of_class +from sqlalchemy.orm.attributes import manager_of_class, instance_state from sqlalchemy.ext.declarative import declarative_base @@ -22,7 +22,11 @@ Base.metadata.create_all(engine) session = sessionmaker(engine)() -e = manager_of_class(Engineer).new_instance() +manager = manager_of_class(Engineer) +e = manager.new_instance() +state = instance_state(e) +manager.mapper._set_polymorphic_identity(state) + session.add(e) session.commit() But this is leaving the area of documented API. I found out that SQLAlchemy actually initializes the polymorphic_identity column by registering an on_init event. I'd rather trigger that but I did not yet find out how to do that. Thanks, Torsten -- DYNAmore Gesellschaft fuer Ingenieurdienstleistungen mbH Torsten Landschoff Office Dresden Tel: +49-(0)351-4519587 Fax: +49-(0)351-4519561 mailto:torsten.landsch...@dynamore.de http://www.dynamore.de Registration court: Stuttgart, HRB 733694 Managing director: Prof. Dr. Karl Schweizerhof, Dipl.-Math. Ulrich Franz -- 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] ClassManager.new_instance does not longer initialize polymorphic column
Hello again,
for a while I want to upgrade our application to use SQLAlchemy 0.7.x.
However I am running into changed behaviour wrt.
ClassManager.new_instance. The behaviour I rely on was discussed here:
http://article.gmane.org/gmane.comp.python.sqlalchemy.user/28746
Basically, I want to create an empty instance of a mapped class and
unserialize my data into it. I am not using Pickle because of security
and compatibility fears.
The attached sample program worked fine with SQLAlchemy 0.6.8:
$ python new_instance.py
<__main__.Engineer object at 0x10774d0>
However, with SQLAlchemy 0.7.5 I get
$ python new_instance.py
Traceback (most recent call last):
File "new_instance.py", line 27, in
session.commit()
[...]
File
"/usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.7.5dev-py2.6-linux-x86_64.egg/sqlalchemy/engine/default.py",
line 330, in do_execute
cursor.execute(statement, parameters)
sqlalchemy.exc.IntegrityError: (IntegrityError) people.type may not be NULL
u'INSERT INTO people (type) VALUES (?)' (None,)
I'd really like to use 0.7.5 but I don't know how to replace
new_instance. I attached the sample program and a suggested patch for
the documentation: In the declarative example, the type column is
nullable.
I found out the hard way that it should rather not be. Having a
non-nullable type column at least unconvers the problem when writing to
the database, not when reading the corrupted database :-)
Greetings, Torsten
--
DYNAmore Gesellschaft fuer Ingenieurdienstleistungen mbH
Torsten Landschoff
Office Dresden
Tel: +49-(0)351-4519587
Fax: +49-(0)351-4519561
mailto:torsten.landsch...@dynamore.de
http://www.dynamore.de
Registration court: Stuttgart, HRB 733694
Managing director: Prof. Dr. Karl Schweizerhof, Dipl.-Math. Ulrich Franz
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from sqlalchemy import *
from sqlalchemy.orm import *
from sqlalchemy.orm.attributes import manager_of_class
from sqlalchemy.ext.declarative import declarative_base
Base = declarative_base()
class Person(Base):
__tablename__ = 'people'
id = Column(Integer, primary_key=True)
discriminator = Column('type', String(50), nullable=False)
__mapper_args__ = {'polymorphic_on': discriminator}
class Engineer(Person):
__tablename__ = 'engineers'
__mapper_args__ = {'polymorphic_identity': 'engineer'}
id = Column(Integer, ForeignKey('people.id'), primary_key=True)
primary_language = Column(String(50))
engine = create_engine("sqlite:///")
Base.metadata.create_all(engine)
session = sessionmaker(engine)()
e = manager_of_class(Engineer).new_instance()
session.add(e)
session.commit()
print session.query(Engineer).first()
diff -r ebe9514a69a4 lib/sqlalchemy/ext/declarative.py
--- a/lib/sqlalchemy/ext/declarative.py Sat Jan 28 17:43:13 2012 -0500
+++ b/lib/sqlalchemy/ext/declarative.py Tue Jan 31 12:50:35 2012 +0100
@@ -389,7 +389,7 @@
class Person(Base):
__tablename__ = 'people'
id = Column(Integer, primary_key=True)
-discriminator = Column('type', String(50))
+discriminator = Column('type', String(50), nullable=False)
__mapper_args__ = {'polymorphic_on': discriminator}
class Engineer(Person):
