[sqlalchemy] Feedback appreciated (again :)
Hi, Lately I've been spending a lot of time improving some SQLAlchemy extensions. I'd appreciate any feedback for the new features I've made. Some of the stuff I've been working on: * Generic relationship support has been added for SQLAlchemy-Utils: http://sqlalchemy-utils.readthedocs.org/en/latest/generic_relationship.html. This is yet another implementation of polymorphic associations pattern (http://techspot.zzzeek.org/2007/05/29/polymorphic-associations-with-sqlalchemy/). It would be very nice to see this kind of implementation in the core of SQLAlchemy some day. What is still needed for the generic_relationship is support for dependency processors and support for different loading strategies. * I added full support for PostgreSQL range data types for SA-Utils: http://sqlalchemy-utils.readthedocs.org/en/latest/range_data_types.html. To be able to handle these datatypes in pythonic way I also created a separate package for handling interval objects on the python side: https://github.com/kvesteri/intervals * Some new database helpers: http://sqlalchemy-utils.readthedocs.org/en/latest/database_helpers.html * http://sqlalchemy-searchable.readthedocs.org/en/latest/ - Humanized search string parsing for PostgreSQL full text search vectors * Lots of new features and tweaks for SQLAlchemy-Continuum: http://sqlalchemy-continuum.readthedocs.org/en/latest/, one especially useful feature is the ActivityPlugin (http://sqlalchemy-continuum.readthedocs.org/en/latest/plugins.html#module-sqlalchemy_continuum.plugins.activity) which uses the generic relationships of SA-Utils. Also thanks Mike for all the hard work you've put into SA 0.9! I love all the new features in the 0.9 series. - Konsta -- You received this message because you are subscribed to the Google Groups sqlalchemy group. To unsubscribe from this group and stop receiving emails from it, send an email to sqlalchemy+unsubscr...@googlegroups.com. To post to this group, send email to sqlalchemy@googlegroups.com. Visit this group at http://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/d/optout.
[sqlalchemy] Could someone please give an example of this paragraph in the Documentation -- Using the session?
I've read this paragraph (http://docs.sqlalchemy.org/en/latest/orm/session.html#unitofwork-cascades) many many times and still can't think of a practical example of what is being discussed. save-update cascade also cascades the *pending history* of the target attribute, meaning that objects which were removed from a scalar or collection attribute whose changes have not yet been flushed are also placed into the target session. This is because they may have foreign key attributes present which will need to be updated to no longer refer to the parent. I don't think my English is the main stumbling block here because I understand the meaning of each word, but as soon as I'm putting them together I'm completely lost. Could someone give a simple example here to illustrate the main point in this paragraph please? Highly appreciated. Thanks. -- You received this message because you are subscribed to the Google Groups sqlalchemy group. To unsubscribe from this group and stop receiving emails from it, send an email to sqlalchemy+unsubscr...@googlegroups.com. To post to this group, send email to sqlalchemy@googlegroups.com. Visit this group at http://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/d/optout.
Re: [sqlalchemy] Could someone please give an example of this paragraph in the Documentation -- Using the session?
you have every reason to be confused by that paragraph, which is using way too
much terminology to express what's important there. at some point, we had to
add a behavior which I thought would be confusing to people, so that paragraph
tries badly to explain what it is. I should replace it with just a simple
sentence and an example. Here's the example:
from sqlalchemy import *
from sqlalchemy.orm import *
from sqlalchemy.ext.declarative import declarative_base
Base = declarative_base()
class A(Base):
__tablename__ = 'a'
id = Column(Integer, primary_key=True)
bs = relationship(B)
class B(Base):
__tablename__ = 'b'
id = Column(Integer, primary_key=True)
a_id = Column(Integer, ForeignKey('a.id'))
e = create_engine(sqlite://, echo=True)
Base.metadata.create_all(e)
sess = Session(e)
a1 = A()
b1 = B()
a1.bs = [b1]
sess.add(a1)
sess.commit()
a1.bs # refresh a1.bs
sess.close() # close out - sess is no longer associated with a1, b1
# all new session
sess2 = Session(e)
a1.bs.remove(b1)
sess2.add(a1)
# b1 was removed from a1.bs, but
# is in sess2 anyway! surprising!
assert b1 in sess2
# because we need it for the flush, it's still here:
from sqlalchemy import inspect
print inspect(a1).attrs.bs.history.deleted
On Mar 15, 2014, at 5:26 AM, Bao Niu niuba...@gmail.com wrote:
I've read this paragraph
(http://docs.sqlalchemy.org/en/latest/orm/session.html#unitofwork-cascades)
many many times and still can't think of a practical example of what is being
discussed.
save-update cascade also cascades the pending history of the target
attribute, meaning that objects which were removed from a scalar or
collection attribute whose changes have not yet been flushed are also placed
into the target session. This is because they may have foreign key attributes
present which will need to be updated to no longer refer to the parent.
I don't think my English is the main stumbling block here because I
understand the meaning of each word, but as soon as I'm putting them together
I'm completely lost. Could someone give a simple example here to illustrate
the main point in this paragraph please? Highly appreciated. Thanks.
--
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Re: [sqlalchemy] Could someone please give an example of this paragraph in the Documentation -- Using the session?
I also appreciate such example! Hope simple terminology with a simple example
can replace the sometimes complicated documentation.
Sent from my i386
On Mar 15, 2014, at 16:31, Michael Bayer mike...@zzzcomputing.com wrote:
you have every reason to be confused by that paragraph, which is using way too
much terminology to express what’s important there. at some point, we had to
add a behavior which I thought would be confusing to people, so that paragraph
tries badly to explain what it is. I should replace it with just a simple
sentence and an example. Here’s the example:
from sqlalchemy import *
from sqlalchemy.orm import *
from sqlalchemy.ext.declarative import declarative_base
Base = declarative_base()
class A(Base):
__tablename__ = 'a'
id = Column(Integer, primary_key=True)
bs = relationship(B)
class B(Base):
__tablename__ = 'b'
id = Column(Integer, primary_key=True)
a_id = Column(Integer, ForeignKey('a.id'))
e = create_engine(sqlite://, echo=True)
Base.metadata.create_all(e)
sess = Session(e)
a1 = A()
b1 = B()
a1.bs = [b1]
sess.add(a1)
sess.commit()
a1.bs # refresh a1.bs
sess.close() # close out - sess is no longer associated with a1, b1
# all new session
sess2 = Session(e)
a1.bs.remove(b1)
sess2.add(a1)
# b1 was removed from a1.bs, but
# is in sess2 anyway! surprising!
assert b1 in sess2
# because we need it for the flush, it's still here:
from sqlalchemy import inspect
print inspect(a1).attrs.bs.history.deleted
On Mar 15, 2014, at 5:26 AM, Bao Niu niuba...@gmail.com wrote:
I've read this paragraph
(http://docs.sqlalchemy.org/en/latest/orm/session.html#unitofwork-cascades)
many many times and still can't think of a practical example of what is being
discussed.
save-update cascade also cascades the pending history of the target
attribute, meaning that objects which were removed from a scalar or
collection attribute whose changes have not yet been flushed are also placed
into the target session. This is because they may have foreign key
attributes present which will need to be updated to no longer refer to the
parent.
I don't think my English is the main stumbling block here because I
understand the meaning of each word, but as soon as I'm putting them together
I'm completely lost. Could someone give a simple example here to illustrate
the main point in this paragraph please? Highly appreciated. Thanks.
--
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Re: [sqlalchemy] Could someone please give an example of this paragraph in the Documentation -- Using the session?
well thats my contribution for today, this is mostly rewritten:
http://sqlalchemy.readthedocs.org/en/rel_0_9/orm/session.html#cascades
On Mar 15, 2014, at 12:07 PM, Gery . gameji...@hotmail.com wrote:
I also appreciate such example! Hope simple terminology with a simple example
can replace the sometimes complicated documentation.
Sent from my i386
On Mar 15, 2014, at 16:31, Michael Bayer mike...@zzzcomputing.com wrote:
you have every reason to be confused by that paragraph, which is using way
too much terminology to express what's important there. at some point, we
had to add a behavior which I thought would be confusing to people, so that
paragraph tries badly to explain what it is. I should replace it with just a
simple sentence and an example. Here's the example:
from sqlalchemy import *
from sqlalchemy.orm import *
from sqlalchemy.ext.declarative import declarative_base
Base = declarative_base()
class A(Base):
__tablename__ = 'a'
id = Column(Integer, primary_key=True)
bs = relationship(B)
class B(Base):
__tablename__ = 'b'
id = Column(Integer, primary_key=True)
a_id = Column(Integer, ForeignKey('a.id'))
e = create_engine(sqlite://, echo=True)
Base.metadata.create_all(e)
sess = Session(e)
a1 = A()
b1 = B()
a1.bs = [b1]
sess.add(a1)
sess.commit()
a1.bs # refresh a1.bs
sess.close() # close out - sess is no longer associated with a1, b1
# all new session
sess2 = Session(e)
a1.bs.remove(b1)
sess2.add(a1)
# b1 was removed from a1.bs, but
# is in sess2 anyway! surprising!
assert b1 in sess2
# because we need it for the flush, it's still here:
from sqlalchemy import inspect
print inspect(a1).attrs.bs.history.deleted
On Mar 15, 2014, at 5:26 AM, Bao Niu niuba...@gmail.com wrote:
I've read this paragraph
(http://docs.sqlalchemy.org/en/latest/orm/session.html#unitofwork-cascades)
many many times and still can't think of a practical example of what is
being discussed.
save-update cascade also cascades the pending history of the target
attribute, meaning that objects which were removed from a scalar or
collection attribute whose changes have not yet been flushed are also placed
into the target session. This is because they may have foreign key
attributes present which will need to be updated to no longer refer to the
parent.
I don't think my English is the main stumbling block here because I
understand the meaning of each word, but as soon as I'm putting them
together I'm completely lost. Could someone give a simple example here to
illustrate the main point in this paragraph please? Highly appreciated.
Thanks.
--
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Re: [sqlalchemy] Could someone please give an example of this paragraph in the Documentation -- Using the session?
Thanks a lot Michael! Just a trivial question here, I noticed in your first
reply you used:
# refresh a1.bs
Why do we need to refresh it? I tried it in my terminal and it doesn't emit
any sql. Is this one if those secret techniques that differentiate a
sqlalchemy ninja and a newbie?;)
On Mar 15, 2014 8:31 AM, Michael Bayer mike...@zzzcomputing.com wrote:
you have every reason to be confused by that paragraph, which is using way
too much terminology to express what's important there. at some point, we
had to add a behavior which I thought would be confusing to people, so that
paragraph tries badly to explain what it is. I should replace it with just
a simple sentence and an example. Here's the example:
from sqlalchemy import *
from sqlalchemy.orm import *
from sqlalchemy.ext.declarative import declarative_base
Base = declarative_base()
class A(Base):
__tablename__ = 'a'
id = Column(Integer, primary_key=True)
bs = relationship(B)
class B(Base):
__tablename__ = 'b'
id = Column(Integer, primary_key=True)
a_id = Column(Integer, ForeignKey('a.id'))
e = create_engine(sqlite://, echo=True)
Base.metadata.create_all(e)
sess = Session(e)
a1 = A()
b1 = B()
a1.bs = [b1]
sess.add(a1)
sess.commit()
a1.bs # refresh a1.bs
sess.close() # close out - sess is no longer associated with a1, b1
# all new session
sess2 = Session(e)
a1.bs.remove(b1)
sess2.add(a1)
# b1 was removed from a1.bs, but
# is in sess2 anyway! surprising!
assert b1 in sess2
# because we need it for the flush, it's still here:
from sqlalchemy import inspect
print inspect(a1).attrs.bs.history.deleted
On Mar 15, 2014, at 5:26 AM, Bao Niu niuba...@gmail.com wrote:
I've read this paragraph (
http://docs.sqlalchemy.org/en/latest/orm/session.html#unitofwork-cascades)
many many times and still can't think of a practical example of what is
being discussed.
save-update cascade also cascades the *pending history* of the target
attribute, meaning that objects which were removed from a scalar or
collection attribute whose changes have not yet been flushed are also
placed into the target session. This is because they may have foreign key
attributes present which will need to be updated to no longer refer to the
parent.
I don't think my English is the main stumbling block here because I
understand the meaning of each word, but as soon as I'm putting them
together I'm completely lost. Could someone give a simple example here to
illustrate the main point in this paragraph please? Highly appreciated.
Thanks.
--
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Re: [sqlalchemy] sql expression performance is bad ?
So, that's the point, my tcp server is single process. Because I have a global dict keep active socket connections, where key is cell device token, and value is the active socket associated with the device. the dict cannot be finely shared between multiple processes.. So, I just pull out db operation and throw into a process pool which only handle db operation. 在 2014年3月16日星期日UTC+8上午4时14分50秒，Michael Bayer写道： On Mar 14, 2014, at 9:18 PM, Ni Wesley nis...@gmail.com javascript: wrote: Seems sqlalchemy engine pool uses thread, eh? SQLAlchemy doesn’t spawn any threads, it only provides library functions which do the thing you ask it to do, synchronously. -- You received this message because you are subscribed to the Google Groups sqlalchemy group. To unsubscribe from this group and stop receiving emails from it, send an email to sqlalchemy+unsubscr...@googlegroups.com. To post to this group, send email to sqlalchemy@googlegroups.com. Visit this group at http://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/d/optout.
