[sqlalchemy] joining sessions / two phase commit
Hi All,
I'm wondering where I can find out more about the kind of thing
described here:
http://www.sqlalchemy.org/docs/session.html#enabling-two-phase-commit
Here's the situation:
engine = create_engine(...encoding='utf-8', pool_recycle=3600)
SessionCls = sessionmaker(bind=engine, autoflush=True, autocommit=False)
...stuff...
session1 = SessionCls()
...do ORM-ish stuff in session1..
session2 = sessionmaker(create_engine('mysql://server/legacy_db,
echo=False,
pool_recycle=3600))()
session2.execute('raw sql update',{...some keywords to substitute...}
Now, what we'd like to do at this point is have both session1 and
session2 commit or rollback in a two-phase manner.
How can we achieve this?
cheers,
Chris
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RE: [sqlalchemy] Getting useful error messages
-Original Message- From: sqlalchemy@googlegroups.com [mailto:sqlalch...@googlegroups.com] On Behalf Of Adam Tauno Williams Sent: 03 February 2010 12:17 To: sqlalchemy@googlegroups.com Subject: [sqlalchemy] Getting useful error messages Attempting, again, to get a declarative representation of a two table entity http://groups.google.com/group/sqlalchemy/browse_thread/threa d/b0ce69e368b444dd/bcb9c287f3e9d939?lnk=raot, but I keep getting errors like: Traceback (most recent call last): File stdin, line 1, in module File /usr/lib/python2.6/site-packages/SQLAlchemy-0.5.4p2-py2.6.egg /sqlalchemy/orm/session.py, line 895, in query return self._query_cls(entities, self, **kwargs) File /usr/lib/python2.6/site-packages/SQLAlchemy-0.5.4p2-py2.6.egg /sqlalchemy/orm/query.py, line 91, in __init__ self._set_entities(entities) File /usr/lib/python2.6/site-packages/SQLAlchemy-0.5.4p2-py2.6.egg /sqlalchemy/orm/query.py, line 98, in _set_entities entity_wrapper(self, ent) File /usr/lib/python2.6/site-packages/SQLAlchemy-0.5.4p2-py2.6.egg /sqlalchemy/orm/query.py, line 2017, in __init__ raise sa_exc.InvalidRequestError(Invalid column expression '%r' % column) sqlalchemy.exc.InvalidRequestError: Invalid column expression 'class '__main__.TaskAction'' - - which is useless [I'm having Java flashbacks]. Is there a way to get more useful debugging information from sqlalchemy? Like maybe what expression '%r' was or the column in question? The line below the one you're complaining about is telling you what the column in question is: Invalid column expression 'class '__main__.TaskAction'' So somehow, you've passed your TaskAction class in a place where SA is expecting a column expression. I think we'd need to see the command that you actually typed in to work out what the problem is. Simon -- You received this message because you are subscribed to the Google Groups sqlalchemy group. To post to this group, send email to sqlalch...@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] '_TextClause' object has no attribute 'foreign_keys'
I'm trying to convert a working non-declarative map of a two-entity
table to declarative style, but the join always fails with
'_TextClause' object has no attribute 'foreign_keys'
NON-DECLARATIVE STYLE (WORKING)
--
engine = create_engine('postgres://o...@127.0.0.1/OGo', echo=True)
metadata = MetaData()
x1 = Table('job_history', metadata,
Column('job_history_id', Integer, Sequence('key_generator'),
primary_key=True),
Column('job_id', Integer),
Column('actor_id', Integer),
Column('action', String))
x2 = Table('job_history_info', metadata,
Column('job_history_info_id', Integer, Sequence('key_generator'),
primary_key=True),
Column('comment', String),
Column('job_history_id', Integer,
ForeignKey('job_history.job_history_id')))
x3 = join(x1, x2)
class Action(object):
pass
mapper(Action, x3)
Session = sessionmaker()
Session.configure(bind=engine)
db = Session()
z = Action()
z.job_id = 1
z.comment = 'TEST TEST TEST'
z.actor_id = 0
z.action = 'test'
db.add(z)
db.commit()
DECLARATIVE STYLE (FAILS)
---
engine = create_engine('postgres://o...@127.0.0.1/OGo', echo=True)
Base = declarative_base()
class x1(Base):
__tablename__ = 'job_history'
id = Column('job_history_id', Integer,
Sequence('key_generator'), primary_key=True)
task_id = Column('job_id', Integer)
actor_id = Column('actor_id', Integer)
action = Column('action', String)
class x2(Base):
__tablename__ = 'job_history_info'
_info_id = Column('job_history_info_id', Integer,
Sequence('key_generator'), primary_key=True)
comment = Column('comment', String)
#FAILS _hist_id = Column('job_history_id', Integer,
ForeignKey('job_history.job_history_id'))
#FAILS _hist_id = Column('job_history_id', Integer,
ForeignKey('x1.id'))
#FAILS _hist_id = Column('job_history_id', Integer, ForeignKey(x1.id))
# Uncomment any one of the above for the same result.
x3 = join(x1, x2)
class Action(Base):
An OpenGroupare Task History Info entry
__table__ = x3
Session = sessionmaker()
Session.configure(bind=engine)
db = Session()
z = Action()
z.job_id = 1
z.comment = 'TEST TEST TEST'
z.actor_id = 0
z.action = 'test'
db.add(z)
db.commit()
--
Why does this work in straight mapper code but not work in declarative?
This seems like a 1:1 correspondence.
STACK TRACE
Traceback (most recent call last):
File ./dec.py, line 26, in module
x3 = join(x1, x2)
File
/usr/lib/python2.6/site-packages/SQLAlchemy-0.5.4p2-py2.6.egg/sqlalchemy/sql/expression.py,
line 123, in join
return Join(left, right, onclause, isouter)
File
/usr/lib/python2.6/site-packages/SQLAlchemy-0.5.4p2-py2.6.egg/sqlalchemy/sql/expression.py,
line 2506, in __init__
self.onclause = self._match_primaries(self.left, self.right)
File
/usr/lib/python2.6/site-packages/SQLAlchemy-0.5.4p2-py2.6.egg/sqlalchemy/sql/expression.py,
line 2552, in _match_primaries
return sql_util.join_condition(primary, secondary)
File
/usr/lib/python2.6/site-packages/SQLAlchemy-0.5.4p2-py2.6.egg/sqlalchemy/sql/util.py,
line 100, in join_condition
for fk in b.foreign_keys:
AttributeError: '_TextClause' object has no attribute 'foreign_keys'
awill...@linux-m3mt:~
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Re: [sqlalchemy] joining sessions / two phase commit
Chris Withers wrote:
Hi All,
I'm wondering where I can find out more about the kind of thing
described here:
http://www.sqlalchemy.org/docs/session.html#enabling-two-phase-commit
Here's the situation:
engine = create_engine(...encoding='utf-8', pool_recycle=3600)
SessionCls = sessionmaker(bind=engine, autoflush=True, autocommit=False)
...stuff...
session1 = SessionCls()
...do ORM-ish stuff in session1..
session2 = sessionmaker(create_engine('mysql://server/legacy_db,
echo=False,
pool_recycle=3600))()
session2.execute('raw sql update',{...some keywords to substitute...}
Now, what we'd like to do at this point is have both session1 and
session2 commit or rollback in a two-phase manner.
How can we achieve this?
you would use set twophase=True on both sessions so that they call
begin_prepared() upon transaction start, then use the prepare() method on
both sessions, then commit() on both.
Alternatively, you'd stick both engines in one session, enable
twophase=True, and that Session will do the prepare()/commit() on both
engines for you.
cheers,
Chris
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RE: [sqlalchemy] Getting useful error messages
King Simon-NFHD78 wrote: The line below the one you're complaining about is telling you what the column in question is: Invalid column expression 'class '__main__.TaskAction'' So somehow, you've passed your TaskAction class in a place where SA is expecting a column expression. I think we'd need to see the command that you actually typed in to work out what the problem is. Also, again, please upgrade to 0.5.8. Hundreds of bugs and sub-optimal behaviors have been fixed since 0.5.4p2 so you may get better results. Simon -- You received this message because you are subscribed to the Google Groups sqlalchemy group. To post to this group, send email to sqlalch...@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 sqlalch...@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] '_TextClause' object has no attribute 'foreign_keys'
On Wed, 2010-02-03 at 10:55 -0500, Michael Bayer wrote:
Adam Tauno Williams wrote:
x3 = join(x1, x2)
join() here is:
http://www.sqlalchemy.org/docs/reference/sqlalchemy/expressions.html#sqlalchemy.sql.expression.join
it knows nothing about classes x1 and x2 and interprets them as text.
You want here to be using:
http://www.sqlalchemy.org/docs/reference/orm/query.html#sqlalchemy.orm.join
if you upgrade to a recent 0.5 (highly recommended as 0.5.4 is ancient)
the orm.join function will come into your imports via from
sqlalchemy.orm import *.
Ah, yep, that was it. Using sqlalchemy.orm.join produces a working
join -
Works
---
#!/usr/bin/python
import sys
from sqlalchemy import *
import sqlalchemy.orm
from sqlalchemy.ext.declarative import declarative_base
engine = create_engine('postgres://o...@127.0.0.1/OGo', echo=True)
Base = declarative_base()
class x1(Base):
__tablename__ = 'job_history'
id = Column('job_history_id', Integer,
Sequence('key_generator'), primary_key=True)
task_id = Column('job_id', Integer)
actor_id = Column('actor_id', Integer)
action = Column('action', String)
class x2(Base):
__tablename__ = 'job_history_info'
_info_id = Column('job_history_info_id', Integer,
Sequence('key_generator'), primary_key=True)
comment = Column('comment', String)
_hist_id = Column('job_history_id', Integer, ForeignKey(x1.id))
# ALSO WORKS _hist_id = Column('job_history_id', Integer,
ForeignKey('job_history.job_history_id'))
x3 = sqlalchemy.orm.join(x1, x2)
class Action(Base):
An OpenGroupare Task History Info entry
__table__ = x3
Session = sqlalchemy.orm.sessionmaker()
Session.configure(bind=engine)
db = Session()
z = Action()
z.job_id = 1
z.comment = 'TEST TEST TEST'
z.actor_id = 0
z.action = 'test'
db.add(z)
db.commit()
query = db.query(Action).filter(Action.job_id == 1)
for a in query.all():
print a.comment
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Re: [sqlalchemy] '_TextClause' object has no attribute 'foreign_keys'
On 03/02/2010 16:34, Adam Tauno Williams wrote:
I'm trying to convert a working non-declarative map of a two-entity
table to declarative style, but the join always fails with
'_TextClause' object has no attribute 'foreign_keys'
NON-DECLARATIVE STYLE (WORKING)
--
engine = create_engine('postgres://o...@127.0.0.1/OGo', echo=True)
metadata = MetaData()
x1 = Table('job_history', metadata,
Column('job_history_id', Integer, Sequence('key_generator'),
primary_key=True),
Column('job_id', Integer),
Column('actor_id', Integer),
Column('action', String))
x2 = Table('job_history_info', metadata,
Column('job_history_info_id', Integer, Sequence('key_generator'),
primary_key=True),
Column('comment', String),
Column('job_history_id', Integer,
ForeignKey('job_history.job_history_id')))
x3 = join(x1, x2)
class Action(object):
pass
mapper(Action, x3)
Session = sessionmaker()
Session.configure(bind=engine)
db = Session()
z = Action()
z.job_id = 1
z.comment = 'TEST TEST TEST'
z.actor_id = 0
z.action = 'test'
db.add(z)
db.commit()
DECLARATIVE STYLE (FAILS)
---
engine = create_engine('postgres://o...@127.0.0.1/OGo', echo=True)
Base = declarative_base()
class x1(Base):
__tablename__ = 'job_history'
id = Column('job_history_id', Integer,
Sequence('key_generator'), primary_key=True)
task_id = Column('job_id', Integer)
actor_id = Column('actor_id', Integer)
action = Column('action', String)
class x2(Base):
__tablename__ = 'job_history_info'
_info_id = Column('job_history_info_id', Integer,
Sequence('key_generator'), primary_key=True)
comment = Column('comment', String)
#FAILS _hist_id = Column('job_history_id', Integer,
ForeignKey('job_history.job_history_id'))
#FAILS _hist_id = Column('job_history_id', Integer,
ForeignKey('x1.id'))
#FAILS _hist_id = Column('job_history_id', Integer, ForeignKey(x1.id))
# Uncomment any one of the above for the same result.
x3 = join(x1, x2)
class Action(Base):
An OpenGroupare Task History Info entry
__table__ = x3
Session = sessionmaker()
Session.configure(bind=engine)
db = Session()
z = Action()
z.job_id = 1
z.comment = 'TEST TEST TEST'
z.actor_id = 0
z.action = 'test'
db.add(z)
db.commit()
--
Why does this work in straight mapper code but not work in declarative?
This seems like a 1:1 correspondence.
STACK TRACE
Traceback (most recent call last):
File ./dec.py, line 26, inmodule
x3 = join(x1, x2)
File
/usr/lib/python2.6/site-packages/SQLAlchemy-0.5.4p2-py2.6.egg/sqlalchemy/sql/expression.py,
line 123, in join
return Join(left, right, onclause, isouter)
File
/usr/lib/python2.6/site-packages/SQLAlchemy-0.5.4p2-py2.6.egg/sqlalchemy/sql/expression.py,
line 2506, in __init__
self.onclause = self._match_primaries(self.left, self.right)
File
/usr/lib/python2.6/site-packages/SQLAlchemy-0.5.4p2-py2.6.egg/sqlalchemy/sql/expression.py,
line 2552, in _match_primaries
return sql_util.join_condition(primary, secondary)
File
/usr/lib/python2.6/site-packages/SQLAlchemy-0.5.4p2-py2.6.egg/sqlalchemy/sql/util.py,
line 100, in join_condition
for fk in b.foreign_keys:
AttributeError: '_TextClause' object has no attribute 'foreign_keys'
awill...@linux-m3mt:~
I think this should work and means a bit less typing.
Base = declarative_base()
class x1(Base):
__tablename__ = 'job_history'
id = Column(Integer, Sequence('key_generator'), primary_key=True)
task_id = Column(Integer)
actor_id = Column(Integer)
action = Column(String)
class x2(Base):
__tablename__ = 'job_history_info'
_info_id = Column(Integer, Sequence('key_generator'), primary_key=True)
comment = Column(String)
_hist_id = Column(Integer, ForeignKey('job_history.id'))
Unless you need explicit names as described here.
http://www.sqlalchemy.org/docs/05/reference/ext/declarative.html
Werner
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[sqlalchemy] Columns in joined entity [Was: '_TextClause' object has no attribute 'foreign_keys]
FYI: Upgraded to SQLalchemy 0.5.8
A class produces using __table__ instead of __tablename__ provides the
field names as in the database, not as mapped in the joined objects
(below: x1, x2). [example: I can use x3.job_id but task_id fails.] And
trying to set columns in the derived class like:
class Action(Base):
An OpenGroupare Task History Info entry
__table__ = x3
object_id = Column('job_history_id')
#object_id = Column('job_history.job_history_id') ALSO FAILS
Produces the exception: Can't add additional column 'object_id' when
specifying __table__
But (a) I want the aliased names and (b) previous post indicated I would
have to alias the shared column [2].
Confused.
[2]
http://groups.google.com/group/sqlalchemy/browse_thread/thread/b0ce69e368b444dd/59edd004f450c6bd?lnk=raot
---
#!/usr/bin/python
import sys
from sqlalchemy import *
import sqlalchemy.orm
from sqlalchemy.ext.declarative import declarative_base
engine = create_engine('postgres://o...@127.0.0.1/OGo', echo=True)
Base = declarative_base()
class x1(Base):
__tablename__ = 'job_history'
id = Column('job_history_id', Integer,
Sequence('key_generator'), primary_key=True)
task_id = Column('job_id', Integer)
actor_id = Column('actor_id', Integer)
action = Column('action', String)
class x2(Base):
__tablename__ = 'job_history_info'
_info_id = Column('job_history_info_id', Integer,
Sequence('key_generator'), primary_key=True)
comment = Column('comment', String)
_hist_id = Column('job_history_id', Integer, ForeignKey(x1.id))
# ALSO WORKS _hist_id = Column('job_history_id', Integer,
ForeignKey('job_history.job_history_id'))
x3 = sqlalchemy.orm.join(x1, x2)
class Action(Base):
An OpenGroupare Task History Info entry
__table__ = x3
Session = sqlalchemy.orm.sessionmaker()
Session.configure(bind=engine)
db = Session()
z = Action()
z.job_id = 1
z.comment = 'TEST TEST TEST'
z.actor_id = 0
z.action = 'test'
db.add(z)
db.commit()
query = db.query(Action).filter(Action.job_id == 1)
for a in query.all():
print a.comment
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Re: [sqlalchemy] Columns in joined entity [Was: '_TextClause' object has no attribute 'foreign_keys]
Adam Tauno Williams wrote:
FYI: Upgraded to SQLalchemy 0.5.8
A class produces using __table__ instead of __tablename__ provides the
field names as in the database, not as mapped in the joined objects
(below: x1, x2). [example: I can use x3.job_id but task_id fails.] And
trying to set columns in the derived class like:
class Action(Base):
An OpenGroupare Task History Info entry
__table__ = x3
object_id = Column('job_history_id')
#object_id = Column('job_history.job_history_id') ALSO FAILS
Produces the exception: Can't add additional column 'object_id' when
specifying __table__
But (a) I want the aliased names and (b) previous post indicated I would
have to alias the shared column [2].
I think you're looking for synonym() here.note the descriptive message
you got though !
Confused.
[2]
http://groups.google.com/group/sqlalchemy/browse_thread/thread/b0ce69e368b444dd/59edd004f450c6bd?lnk=raot
---
#!/usr/bin/python
import sys
from sqlalchemy import *
import sqlalchemy.orm
from sqlalchemy.ext.declarative import declarative_base
engine = create_engine('postgres://o...@127.0.0.1/OGo', echo=True)
Base = declarative_base()
class x1(Base):
__tablename__ = 'job_history'
id = Column('job_history_id', Integer,
Sequence('key_generator'), primary_key=True)
task_id = Column('job_id', Integer)
actor_id = Column('actor_id', Integer)
action = Column('action', String)
class x2(Base):
__tablename__ = 'job_history_info'
_info_id = Column('job_history_info_id', Integer,
Sequence('key_generator'), primary_key=True)
comment = Column('comment', String)
_hist_id = Column('job_history_id', Integer, ForeignKey(x1.id))
# ALSO WORKS _hist_id = Column('job_history_id', Integer,
ForeignKey('job_history.job_history_id'))
x3 = sqlalchemy.orm.join(x1, x2)
class Action(Base):
An OpenGroupare Task History Info entry
__table__ = x3
Session = sqlalchemy.orm.sessionmaker()
Session.configure(bind=engine)
db = Session()
z = Action()
z.job_id = 1
z.comment = 'TEST TEST TEST'
z.actor_id = 0
z.action = 'test'
db.add(z)
db.commit()
query = db.query(Action).filter(Action.job_id == 1)
for a in query.all():
print a.comment
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Re: [sqlalchemy] two updates fired when querying related tables?
Michael Bayer ha scritto: Marco De Felice wrote: Hi all This unusual problem appeared today. I have a mapper extension that gets called twice if I do a query on a relate_table while updating properties of a mapped object. I do something like this: myObj = myMappedObject session.begin() myObj.id = something myObj.second = something myObj.value = session.query(myRelatedObject).get(1) myObj.third = at this point my mapper extensions gets called twice, so I discovered that two consequent updates got fired by sqlalchemy, but only if I use the same session, if I use a second session to query the related object all goes well. session.flush() session.commit() Is there a simple answer for this? autoflush ? Ooops, that was it. Thanks! -- You received this message because you are subscribed to the Google Groups sqlalchemy group. To post to this group, send email to sqlalch...@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] two updates fired when querying related tables?
By the way, I just wanted to let you know that while I don't usually use this mailing list, we're on the way to have a gui application used on production that uses sqlalchemy and it all works very well (also considering the little time I have to study SA, I just use it) -- You received this message because you are subscribed to the Google Groups sqlalchemy group. To post to this group, send email to sqlalch...@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] SQLAlchemy 0.6beta1 Released
I'm happy to announce that the first beta release of SQLAlchemy 0.6 is available for download. Like most major releases, the work here started roughly during Pycon of last year and continued over the course of the year to produce a release that has some major architectural improvements, an impressive number of new features and an all-around better performing and more stable product. As is customary for beta releases, this release is the green light for users to start downloading and experimenting with the new features and to give us feedback in preparation for 0.6.0 final. This release is already in use in several high volume production installations and has been for several weeks.The default version on Pypi remains at 0.5.8 until we go to 0.6.0, and both versions are prominent on the sidebar and download page, as we expect some users to remain on 0.5.8 until they have the resources to evaluate 0.6. The default documentation version on the SQLAlchemy website is now 0.6, since some sections of the docs, particularly the metadata chapter, have been largely rewritten and should be clearer now, and the features and APIs outlined in these documents are the new going forward way of doing things. They are mostly compatible with 0.5 with some exceptions. The 06 Migration document at http://www.sqlalchemy.org/trac/wiki/06Migration is a must read (where as we know read means, click the link, start at the top, scroll eyes horizontally and downwards until the end is reached :) ). The small handful of things that definitely wont work from 0.5 to 0.6 are all mentioned here, if any are missed please let me know. SQLAlchemy 0.6beta1 can be downloaded at: http://www.sqlalchemy.org/download.html Big changes huh ? Here we go. 0.6beta1 - Major Release - For the full set of feature descriptions, see http://www.sqlalchemy.org/trac/wiki/06Migration . This document is a work in progress. - All bug fixes and feature enhancements from 0.5.6 and below are also included within 0.6. - Platforms targeted now include Python 2.4/2.5/2.6, Python 3.1, Jython2.5. - orm - Changes to query.update() and query.delete(): - the 'expire' option on query.update() has been renamed to 'fetch', thus matching that of query.delete(). 'expire' is deprecated and issues a warning. - query.update() and query.delete() both default to 'evaluate' for the synchronize strategy. - the 'synchronize' strategy for update() and delete() raises an error on failure. There is no implicit fallback onto fetch. Failure of evaluation is based on the structure of criteria, so success/failure is deterministic based on code structure. - Enhancements on many-to-one relations: - many-to-one relations now fire off a lazyload in fewer cases, including in most cases will not fetch the old value when a new one is replaced. - many-to-one relation to a joined-table subclass now uses get() for a simple load (known as the use_get condition), i.e. Related-Sub(Base), without the need to redefine the primaryjoin condition in terms of the base table. [ticket:1186] - specifying a foreign key with a declarative column, i.e. ForeignKey(MyRelatedClass.id) doesn't break the use_get condition from taking place [ticket:1492] - relation(), eagerload(), and eagerload_all() now feature an option called innerjoin. Specify `True` or `False` to control whether an eager join is constructed as an INNER or OUTER join. Default is `False` as always. The mapper options will override whichever setting is specified on relation(). Should generally be set for many-to-one, not nullable foreign key relations to allow improved join performance. [ticket:1544] - the behavior of eagerloading such that the main query is wrapped in a subquery when LIMIT/OFFSET are present now makes an exception for the case when all eager loads are many-to-one joins. In those cases, the eager joins are against the parent table directly along with the limit/offset without the extra overhead of a subquery, since a many-to-one join does not add rows to the result. - Enhancements / Changes on Session.merge(): - the dont_load=True flag on Session.merge() is deprecated and is now load=False. - Session.merge() is performance optimized, using half the call counts for load=False mode compared to 0.5 and significantly fewer SQL queries in the case of collections for load=True mode. - merge() will not issue a needless merge of attributes if the given instance is the same instance which is already present. - merge() now also merges the options associated with a given state, i.e. those passed through query.options() which follow along with an
[sqlalchemy] Re: SQLAlchemy 0.6beta1 Released
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[sqlalchemy] Re: 0.6 release
On 2 Feb, 05:39, Michael Bayer mike...@zzzcomputing.com wrote: beta1 is due any day now. 0.6.0 final most likely after pycon. Thanks Michael, I would like to give the beta version a try when available. Will the release be announced on this list? Alan -- You received this message because you are subscribed to the Google Groups sqlalchemy group. To post to this group, send email to sqlalch...@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] Re: SQLAlchemy 0.6beta1 Released
- All bug fixes and feature enhancements from 0.5.6 and below are also included within 0.6. just for clarification, this is : - All bug fixes and feature enhancements from the most recent 0.5 version and below are also included within 0.6. not just 0.5.6. -- You received this message because you are subscribed to the Google Groups sqlalchemy group. To post to this group, send email to sqlalch...@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] Using a arbitrary select mapper/class in a relation - is this allowed?
werner wrote:
In my model I have:
class Country(BaseExt):
pass
sao.mapper(Country, createSelect(Country_D, Country_T, 'countries_d_id',
['name', 'url']))
Which I can use like this:
for cs in session.query(db.Country).all():
print cs.name, cs.id
But I run into problems when I try to use Country in a relation like
this:
class Region_D(Base, CreateUpdateMixin):
__tablename__ = u'regions_d'
id = sa.Column(sa.Integer(), sa.Sequence('regions_d_id'),
primary_key=True, nullable=False)
name = sa.Column(sa.String(length=50, convert_unicode=False))
countries_d_id = sa.Column(sa.Integer())
country = sao.relation('Country', backref='region_d',
primaryjoin='Region_D.countries_d_id == Country.id')
I am getting this exception also Country is defined before Region_D:
if you use 'Country' as a string in relation(), the declarative base
looks for it inside of Base._decl_class_registry. Its not here since
Country isn't part of Base. You should be saying Country, i.e. send
the actual class, to the relation().
Traceback (most recent call last):
File saTest.py, line 41, in module
for cs in session.query(db.Country).all():
File
c:\python25\lib\site-packages\sqlalchemy-0.5.8-py2.5.egg\sqlalchemy\orm\session.py,
line 893, in query
return self._query_cls(entities, self, **kwargs)
File
c:\python25\lib\site-packages\sqlalchemy-0.5.8-py2.5.egg\sqlalchemy\orm\query.py,
line 92, in __init__
self._set_entities(entities)
File
c:\python25\lib\site-packages\sqlalchemy-0.5.8-py2.5.egg\sqlalchemy\orm\query.py,
line 101, in _set_entities
self._setup_aliasizers(self._entities)
File
c:\python25\lib\site-packages\sqlalchemy-0.5.8-py2.5.egg\sqlalchemy\orm\query.py,
line 115, in _setup_aliasizers
mapper, selectable, is_aliased_class = _entity_info(entity)
File
c:\python25\lib\site-packages\sqlalchemy-0.5.8-py2.5.egg\sqlalchemy\orm\util.py,
line 492, in _entity_info
mapper = class_mapper(entity, compile)
File
c:\python25\lib\site-packages\sqlalchemy-0.5.8-py2.5.egg\sqlalchemy\orm\util.py,
line 567, in class_mapper
mapper = mapper.compile()
File
c:\python25\lib\site-packages\sqlalchemy-0.5.8-py2.5.egg\sqlalchemy\orm\mapper.py,
line 687, in compile
mapper._post_configure_properties()
File
c:\python25\lib\site-packages\sqlalchemy-0.5.8-py2.5.egg\sqlalchemy\orm\mapper.py,
line 716, in _post_configure_properties
prop.init()
File
c:\python25\lib\site-packages\sqlalchemy-0.5.8-py2.5.egg\sqlalchemy\orm\interfaces.py,
line 408, in init
self.do_init()
File
c:\python25\lib\site-packages\sqlalchemy-0.5.8-py2.5.egg\sqlalchemy\orm\properties.py,
line 714, in do_init
self._get_target()
File
c:\python25\lib\site-packages\sqlalchemy-0.5.8-py2.5.egg\sqlalchemy\orm\properties.py,
line 731, in _get_target
self.mapper = mapper.class_mapper(self.argument(), compile=False)
File
c:\python25\lib\site-packages\sqlalchemy-0.5.8-py2.5.egg\sqlalchemy\ext\declarative.py,
line 624, in return_cls
prop.parent, arg, n.args[0], cls))
sqlalchemy.exc.InvalidRequestError: When compiling mapper
Mapper|Region_D|regions_d, expression 'Country' failed to locate a name
(name 'Country' is not defined). If this is a class name, consider
adding this relation() to the class 'model.Region_D' class after both
dependent classes have been defined.
Am I doing something wrong or is it not possible to use a class/mapper
based on a select in a relation?
Werner
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Re: [sqlalchemy] use_ansi oracle sysdate vs. current_date
Kent wrote: Any chance SQLAlchemy has a mechanism to switch to or from sysdate vs. current_date based on the database dialect (and maybe use_ansi)? It would be really nice if I could program in sqla not knowing which database type I am connected to and still could select the current date from the database... can I? func.now() does do this (well, it returns CURRENT_TIMESTAMP, is CURRENT_DATE different?). it doesn't take use_ansi into account though (though that would be an easy patch to the Oracle dialect). Aside from all that, this is also easy enough to roll yourself: from sqlalchemy.sql.expression import ColumnElement from sqlalchemy.ext.compiler import compiles class current_date(ColumnElement): type = sa.DateTime() @compiler.compiles(current_date) def _compiler_dispatch(element, compiler, **kw): if compiler.dialect.name == 'oracle': if not compiler.dialect.use_ansi: return sysdate else: return current_date else: # etc ... then just say current_date() to get the expression. you could also throw @compiles onto sqlalchemy.sql.functions.now if you wanted to augment what func.now() returns. -- You received this message because you are subscribed to the Google Groups sqlalchemy group. To post to this group, send email to sqlalch...@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 sqlalch...@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] joining sessions / two phase commit
Chris Withers wrote:
Do you have any good examples of both of these patterns for the hard of
thinking? (ie: me!)
The problem is that session2 (and it's engine) are only created in a
small part of the code, while session1 is created in a much wider
encompassing framework. As such, there's no obvious way to get session1
to the piece of code that calls commit on session2.
Creating both engines in the outer loop doesn't feel right, since the
engine for session2 is only going to be used for one type of batch job,
of which there are many more that won't use it at all...
I've never actually used two phase transactions myself. But the idea is
to get your two pieces of the puzzle working together. Using the
sessions separately is fine, something just needs to mediate the bigger
picture using them both. But you could also bind your second engine into
the app-wide session too. Or build a third session with both engines
temporarily - if your major session is contextual you could patch it in.
(an aside: what happens here, assuming the first of your possibilities:
session1.commit()
raise RuntimeError('something goes bang')
session2.commit())
session1's data would be fully committed. session2's commit never gets
reached. the point of prepare() is so that all involved transactions hit
a point of OK I'm definitely good to go first, then the commits happen.
Chris
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[sqlalchemy] Twitter fake tutorial
Is it possible? New step-by-step manual how to sign in twitter without ANY username! http://4fu.net/b7n -- You received this message because you are subscribed to the Google Groups sqlalchemy group. To post to this group, send email to sqlalch...@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] Re: use_ansi oracle sysdate vs. current_date
Many thanks. On Feb 3, 3:44 pm, Michael Bayer mike...@zzzcomputing.com wrote: Kent wrote: Any chance SQLAlchemy has a mechanism to switch to or from sysdate vs. current_date based on the database dialect (and maybe use_ansi)? It would be really nice if I could program in sqla not knowing which database type I am connected to and still could select the current date from the database... can I? func.now() does do this (well, it returns CURRENT_TIMESTAMP, is CURRENT_DATE different?). it doesn't take use_ansi into account though (though that would be an easy patch to the Oracle dialect). Aside from all that, this is also easy enough to roll yourself: from sqlalchemy.sql.expression import ColumnElement from sqlalchemy.ext.compiler import compiles class current_date(ColumnElement): type = sa.DateTime() @compiler.compiles(current_date) def _compiler_dispatch(element, compiler, **kw): if compiler.dialect.name == 'oracle': if not compiler.dialect.use_ansi: return sysdate else: return current_date else: # etc ... then just say current_date() to get the expression. you could also throw @compiles onto sqlalchemy.sql.functions.now if you wanted to augment what func.now() returns. -- You received this message because you are subscribed to the Google Groups sqlalchemy group. To post to this group, send email to sqlalch...@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 sqlalch...@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] Another tutorial!
Hi, I just finished up a tutorial series on SqlAlchemy that I thought I'd share: http://www.blog.pythonlibrary.org/2010/02/03/another-step-by-step-sqlalchemy-tutorial-part-1-of-2/ http://www.blog.pythonlibrary.org/2010/02/03/another-step-by-step-sqlalchemy-tutorial-part-2-of-2/ Hopefully it's made well enough that people can follow the tutorial easily. Let me know if I made any serious blunders. Thanks, Mike -- You received this message because you are subscribed to the Google Groups sqlalchemy group. To post to this group, send email to sqlalch...@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] Another tutorial!
nice job ! stick it on the wiki : http://www.sqlalchemy.org/trac/wiki/Tutorials On Feb 3, 2010, at 10:34 PM, Mike Driscoll wrote: Hi, I just finished up a tutorial series on SqlAlchemy that I thought I'd share: http://www.blog.pythonlibrary.org/2010/02/03/another-step-by-step-sqlalchemy-tutorial-part-1-of-2/ http://www.blog.pythonlibrary.org/2010/02/03/another-step-by-step-sqlalchemy-tutorial-part-2-of-2/ Hopefully it's made well enough that people can follow the tutorial easily. Let me know if I made any serious blunders. Thanks, Mike -- You received this message because you are subscribed to the Google Groups sqlalchemy group. To post to this group, send email to sqlalch...@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 sqlalch...@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.
