[sqlalchemy] Re: set_shard problems
Excellent work! Indeed r5335 did fix the problem. Thank you very much for your help. Regards, Ids --~--~-~--~~~---~--~~ 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: Invalid Request Error at session level.
On Nov 28, 2008, at 1:42 AM, Harish Vishwanath wrote: I am guarding my commits with a mutex, if you are using one session per thread then there is no need to use mutexing. but the queries are unguarded. if you are using a single Query object in multiple threads simultaneously, that will be problematic, since their usage, as well as usage of the objects produced by the Query, constitutes session access, as in when rows are loaded. Especially if autoflush is turned on then you'd essentially be using the Session in a completely thread-unsafe manner. If one of the session is committing on the database and the other one is trying to query, would this problem arise? there is no issue with this as long as all Session, Query and persistent instance is maintained local to a single thread. Issues at the level of concurrent transaction contention are handled by the database (and this error is not related to that). I am not very sure on how connection objects are created during this scenario. Appreciate your help. The Session typically references a single database connection throughout the lifespan of a transaction. when the transaction completes, the connection is returned to the pool. The actual transaction state of the Session is determined by the configuration flag autocommit=False as well as the begin()/commit() methods. These are described in the docs. --~--~-~--~~~---~--~~ 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] offline metadata configuration, change storage and metadata snapshot.
Hi All I'm writing a program for graphically configuring database schemas. To do this, I want to use the sqlalchemy schema.py objects to store my metadata as its changed and modified. To do this, I think i will need three things. 1. Apply the meta data changes to a development database, As this is the easiest way to ensure integrity as you are reconfiguring the structure. 2. Store incremental changes to the metadata 3. Snapshot the metadata to a file so it can be restored. Does SQL Alchemy currently have any facilities to help me achieve items 2 and 3? Regards, Jar --~--~-~--~~~---~--~~ 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: offline metadata configuration, change storage and metadata snapshot.
On Nov 28, 2008, at 6:58 AM, [EMAIL PROTECTED] wrote: Hi All I'm writing a program for graphically configuring database schemas. To do this, I want to use the sqlalchemy schema.py objects to store my metadata as its changed and modified. To do this, I think i will need three things. 1. Apply the meta data changes to a development database, As this is the easiest way to ensure integrity as you are reconfiguring the structure. 2. Store incremental changes to the metadata 3. Snapshot the metadata to a file so it can be restored. Does SQL Alchemy currently have any facilities to help me achieve items 2 and 3? for #1 and #2, you want to use sqlalchemy-migrate at http://code.google.com/p/sqlalchemy-migrate/ . For #3, the metadata object can be pickled, and for more sophisticated serilalization of expression and ORM constructs there is also a serializer extension in 0.5, documented at http://www.sqlalchemy.org/docs/05/plugins.html#plugins_serializer . --~--~-~--~~~---~--~~ 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: offline metadata configuration, change storage and metadata snapshot.
Thanks. I thought of using pickle but it says not everything can be picked, So i was concerned the metadata objects might be in the unlucky group. The other problem i have with pickle is what happens when i upgrade to a newer version of sqlAlchemy some of the metadata objects might change. How does pickle handle this? My other idea instead of pickle was to write code to map it out and store it in a SQL lite or xml, Then i could patch it so it could be restored to the never version of sqlAlchemy. Thanks heaps again for the help, Regards, Jar On Nov 29, 1:56 am, Michael Bayer [EMAIL PROTECTED] wrote: On Nov 28, 2008, at 6:58 AM, [EMAIL PROTECTED] wrote: Hi All I'm writing a program for graphically configuring database schemas. To do this, I want to use the sqlalchemy schema.py objects to store my metadata as its changed and modified. To do this, I think i will need three things. 1. Apply the meta data changes to a development database, As this is the easiest way to ensure integrity as you are reconfiguring the structure. 2. Store incremental changes to the metadata 3. Snapshot the metadata to a file so it can be restored. Does SQL Alchemy currently have any facilities to help me achieve items 2 and 3? for #1 and #2, you want to use sqlalchemy-migrate athttp://code.google.com/p/sqlalchemy-migrate/ . For #3, the metadata object can be pickled, and for more sophisticated serilalization of expression and ORM constructs there is also a serializer extension in 0.5, documented athttp://www.sqlalchemy.org/docs/05/plugins.html#plugins_serializer . --~--~-~--~~~---~--~~ 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] New instance ExtraStat with identity key (...) conflicts with persistent instance ExtraStat
Hi all,
I'm having a problem with a new instance of a relation conflicting with
an existing instance. I'm using SA 0.5rc with Sqlite3. Here are my
simplified classes:
class Stat(sqladb.Base):
__tablename__ = stats
name = Column(String(32), primary_key=True)
total= Column(Integer)
created = Column(DateTime, default=datetime.datetime.now())
updated = Column(DateTime)
states = Column(PickleType, default={})
extraStats = relation(ExtraStat, backref=stat)
class ExtraStat(sqladb.Base):
__tablename__ = extrastats
name = Column(String(32), ForeignKey(stats.name),
primary_key=True)
total= Column(Integer)
created = Column(DateTime, default=datetime.datetime.now())
updated = Column(DateTime)
states = Column(PickleType, default={})
The above Stat class has a one-to-many relationship with the ExtraStat
class (which I think I've implemented correctly). Later in the program I
create an in memory data model that has as part of it's components two
dictionaries that contain Stat instances. Those Stat instances have
relationships to ExtraStat instances. My problem comes in the following
when I'm trying to update the data in those instances/tables. Here is a
section of code that throws the exception:
pressName = press%s % pressNum
# add new ExtraStat instances as relations
self._addProductStatsPress(productType, pressName)
self._addPressStatsProduct(pressName, productType)
try:
extraStat = session.query(Stat). \
filter(Stat.name==productType). \
join(extraStats). \
filter(ExtraStat.name==pressName).one()
except:
extraStat = ExtraStat(pressName, ExtraStat.PRESS_TYPE)
self.productStats[productType].extraStats.append(extraStat)
extraStat.states.setdefault(sstate, 0)
extraStat.states[sstate] += 1
extraStat.updated = now
extraStat = session.merge(extraStat)
try:
extraStat = session.query(Stat). \
filter(Stat.name==pressName). \
join(extraStats). \
filter(ExtraStat.name==productType).one() throws
exception right here
except:
extraStat = ExtraStat(productType, ExtraStat.PRODUCT_TYPE)
self.pressStats[pressName].extraStats.append(extraStat)
extraStat.states.setdefault(sstate, 0)
extraStat.states[sstate] += 1
extraStat.updated = now
The marked area is wear it throws the exception. I'm not sure what to do
here to get past this, any help or ideas would be greatly appreciated.
The exact exception is as follows:
Sqlalchemy.orm.exc.FlushError: New instance [EMAIL PROTECTED] With identity
key (class '__main__.ExtraStat',(u'C',)) conflicts with persistent
instance [EMAIL PROTECTED]
Thanks!
Doug
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[sqlalchemy] Re: New instance ExtraStat with identity key (...) conflicts with persistent instance ExtraStat
-Original Message-
From: sqlalchemy@googlegroups.com
[mailto:[EMAIL PROTECTED] On Behalf Of Doug Farrell
Sent: 28 November 2008 18:22
To: sqlalchemy@googlegroups.com
Subject: [sqlalchemy] New instance ExtraStat with identity
key (...) conflicts with persistent instance ExtraStat
Hi all,
I'm having a problem with a new instance of a relation
conflicting with
an existing instance. I'm using SA 0.5rc with Sqlite3. Here are my
simplified classes:
class Stat(sqladb.Base):
__tablename__ = stats
name = Column(String(32), primary_key=True)
total= Column(Integer)
created = Column(DateTime, default=datetime.datetime.now())
updated = Column(DateTime)
states = Column(PickleType, default={})
extraStats = relation(ExtraStat, backref=stat)
class ExtraStat(sqladb.Base):
__tablename__ = extrastats
name = Column(String(32), ForeignKey(stats.name),
primary_key=True)
total= Column(Integer)
created = Column(DateTime, default=datetime.datetime.now())
updated = Column(DateTime)
states = Column(PickleType, default={})
The above Stat class has a one-to-many relationship with the ExtraStat
class (which I think I've implemented correctly). Later in
the program I
create an in memory data model that has as part of it's components two
dictionaries that contain Stat instances. Those Stat instances have
relationships to ExtraStat instances. My problem comes in the
following
when I'm trying to update the data in those instances/tables.
Here is a
section of code that throws the exception:
pressName = press%s % pressNum
# add new ExtraStat instances as relations
self._addProductStatsPress(productType, pressName)
self._addPressStatsProduct(pressName, productType)
try:
extraStat = session.query(Stat). \
filter(Stat.name==productType). \
join(extraStats). \
filter(ExtraStat.name==pressName).one()
except:
extraStat = ExtraStat(pressName, ExtraStat.PRESS_TYPE)
self.productStats[productType].extraStats.append(extraStat)
extraStat.states.setdefault(sstate, 0)
extraStat.states[sstate] += 1
extraStat.updated = now
extraStat = session.merge(extraStat)
try:
extraStat = session.query(Stat). \
filter(Stat.name==pressName). \
join(extraStats). \
filter(ExtraStat.name==productType).one() throws
exception right here
except:
extraStat = ExtraStat(productType, ExtraStat.PRODUCT_TYPE)
self.pressStats[pressName].extraStats.append(extraStat)
extraStat.states.setdefault(sstate, 0)
extraStat.states[sstate] += 1
extraStat.updated = now
The marked area is wear it throws the exception. I'm not sure
what to do
here to get past this, any help or ideas would be greatly appreciated.
The exact exception is as follows:
Sqlalchemy.orm.exc.FlushError: New instance [EMAIL PROTECTED]
With identity
key (class '__main__.ExtraStat',(u'C',)) conflicts with persistent
instance [EMAIL PROTECTED]
Thanks!
Doug
This may not be the cause of your problem, but with your mapping above,
I think you can only have one ExtraStat per Stat, because they have the
same primary key (the 'name' column). If 'name' is the only thing that
uniquely distinguishes an ExtraStat, you can only have one per name.
Hope that helps,
Simon
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[sqlalchemy] query.with_polymorphic()
what should query.with_polymorphic generate? e.g. given query(A).with_polymorphic( B,D) it does something like select ... from A left outer join B left outer join D and no discriminator filter.. which includes all A's regardless of their type... svil --~--~-~--~~~---~--~~ 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: query.with_polymorphic()
with_polymorphic doesn't limit what classes are loaded. It only controls how the SQL is rendered such that fewer subsequent queries are needed when attributes are referenced on the resulting objects, and also so that you can specify filtering criterion on those joined tables. On Nov 28, 2008, at 3:51 PM, [EMAIL PROTECTED] wrote: what should query.with_polymorphic generate? e.g. given query(A).with_polymorphic( B,D) it does something like select ... from A left outer join B left outer join D and no discriminator filter.. which includes all A's regardless of their type... svil --~--~-~--~~~---~--~~ 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: New instance ExtraStat with identity key (...) conflicts with persistent instance ExtraStat
What was your justification of changing the name of my thread to a
completely different topic instead of starting a new thread?
I don't think thats good etiquette.
On Nov 29, 5:22 am, Doug Farrell [EMAIL PROTECTED] wrote:
Hi all,
I'm having a problem with a new instance of a relation conflicting with
an existing instance. I'm using SA 0.5rc with Sqlite3. Here are my
simplified classes:
class Stat(sqladb.Base):
__tablename__ = stats
name = Column(String(32), primary_key=True)
total= Column(Integer)
created = Column(DateTime, default=datetime.datetime.now())
updated = Column(DateTime)
states = Column(PickleType, default={})
extraStats = relation(ExtraStat, backref=stat)
class ExtraStat(sqladb.Base):
__tablename__ = extrastats
name = Column(String(32), ForeignKey(stats.name),
primary_key=True)
total= Column(Integer)
created = Column(DateTime, default=datetime.datetime.now())
updated = Column(DateTime)
states = Column(PickleType, default={})
The above Stat class has a one-to-many relationship with the ExtraStat
class (which I think I've implemented correctly). Later in the program I
create an in memory data model that has as part of it's components two
dictionaries that contain Stat instances. Those Stat instances have
relationships to ExtraStat instances. My problem comes in the following
when I'm trying to update the data in those instances/tables. Here is a
section of code that throws the exception:
pressName = press%s % pressNum
# add new ExtraStat instances as relations
self._addProductStatsPress(productType, pressName)
self._addPressStatsProduct(pressName, productType)
try:
extraStat = session.query(Stat). \
filter(Stat.name==productType). \
join(extraStats). \
filter(ExtraStat.name==pressName).one()
except:
extraStat = ExtraStat(pressName, ExtraStat.PRESS_TYPE)
self.productStats[productType].extraStats.append(extraStat)
extraStat.states.setdefault(sstate, 0)
extraStat.states[sstate] += 1
extraStat.updated = now
extraStat = session.merge(extraStat)
try:
extraStat = session.query(Stat). \
filter(Stat.name==pressName). \
join(extraStats). \
filter(ExtraStat.name==productType).one() throws
exception right here
except:
extraStat = ExtraStat(productType, ExtraStat.PRODUCT_TYPE)
self.pressStats[pressName].extraStats.append(extraStat)
extraStat.states.setdefault(sstate, 0)
extraStat.states[sstate] += 1
extraStat.updated = now
The marked area is wear it throws the exception. I'm not sure what to do
here to get past this, any help or ideas would be greatly appreciated.
The exact exception is as follows:
Sqlalchemy.orm.exc.FlushError: New instance [EMAIL PROTECTED] With identity
key (class '__main__.ExtraStat',(u'C',)) conflicts with persistent
instance [EMAIL PROTECTED]
Thanks!
Doug
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[sqlalchemy] Re: New instance ExtraStat with identity key (...) conflicts with persistent instance ExtraStat
What was your justification of changing the name of my thread to a
completely different topic instead of starting a new thread?
I don't think thats good etiquette.
On Nov 29, 5:22 am, Doug Farrell [EMAIL PROTECTED] wrote:
Hi all,
I'm having a problem with a new instance of a relation conflicting with
an existing instance. I'm using SA 0.5rc with Sqlite3. Here are my
simplified classes:
class Stat(sqladb.Base):
__tablename__ = stats
name = Column(String(32), primary_key=True)
total= Column(Integer)
created = Column(DateTime, default=datetime.datetime.now())
updated = Column(DateTime)
states = Column(PickleType, default={})
extraStats = relation(ExtraStat, backref=stat)
class ExtraStat(sqladb.Base):
__tablename__ = extrastats
name = Column(String(32), ForeignKey(stats.name),
primary_key=True)
total= Column(Integer)
created = Column(DateTime, default=datetime.datetime.now())
updated = Column(DateTime)
states = Column(PickleType, default={})
The above Stat class has a one-to-many relationship with the ExtraStat
class (which I think I've implemented correctly). Later in the program I
create an in memory data model that has as part of it's components two
dictionaries that contain Stat instances. Those Stat instances have
relationships to ExtraStat instances. My problem comes in the following
when I'm trying to update the data in those instances/tables. Here is a
section of code that throws the exception:
pressName = press%s % pressNum
# add new ExtraStat instances as relations
self._addProductStatsPress(productType, pressName)
self._addPressStatsProduct(pressName, productType)
try:
extraStat = session.query(Stat). \
filter(Stat.name==productType). \
join(extraStats). \
filter(ExtraStat.name==pressName).one()
except:
extraStat = ExtraStat(pressName, ExtraStat.PRESS_TYPE)
self.productStats[productType].extraStats.append(extraStat)
extraStat.states.setdefault(sstate, 0)
extraStat.states[sstate] += 1
extraStat.updated = now
extraStat = session.merge(extraStat)
try:
extraStat = session.query(Stat). \
filter(Stat.name==pressName). \
join(extraStats). \
filter(ExtraStat.name==productType).one() throws
exception right here
except:
extraStat = ExtraStat(productType, ExtraStat.PRODUCT_TYPE)
self.pressStats[pressName].extraStats.append(extraStat)
extraStat.states.setdefault(sstate, 0)
extraStat.states[sstate] += 1
extraStat.updated = now
The marked area is wear it throws the exception. I'm not sure what to do
here to get past this, any help or ideas would be greatly appreciated.
The exact exception is as follows:
Sqlalchemy.orm.exc.FlushError: New instance [EMAIL PROTECTED] With identity
key (class '__main__.ExtraStat',(u'C',)) conflicts with persistent
instance [EMAIL PROTECTED]
Thanks!
Doug
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