Re: [sqlalchemy] [Q][0.7.9] How to issue apply_labels() on an ORM query?
On Friday, May 31, 2013 11:46:46 AM UTC+2, Ladislav Lenart wrote: Glad I could help, but I don't understand what is going on. Neither ticket description nor the patch itself helped me. Sorry. What is select_from() good for when it generates a cartesian query? What MIGHT help ME (a lot infact) is a couple of DOs and DONTs examples in one place for all these three constructs OR A 'highlevel user-friendly step-by-step description' about what each construct does, so that I can see where they differ. Hi, Lenart! In the patch you can find doc for the new method Query.select_entity_from. As I read it, it replaces Query.select_from. Have you tried simply replacing old method with the new one (after applying the patch)? a. -- 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?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
Re: [sqlalchemy] [Q][0.7.9] How to issue apply_labels() on an ORM query?
On Fri, May 31, 2013 at 12:31 PM, Ladislav Lenart lenart...@volny.czwrote: Hello. I've read the patch and the new documentation and i've learned about the existence of select_entity_from(). I was trying to say that the new documentation does not help me to understand the meaning / preferred usage of these constructs (i.e. select_from, select_entity_from and aliased). I simply don't understand when should I use which and why. I have already solved my original problem by replacing select_from() with add_entity() and join(). Take a look at older posts in this thread for more details if you're interested, though the original query is a bit more involved than the supplied regression. Ladislav Lenart Sorry I rushed with the reply! I haven't carefully read your original post, but concentrated on the patch as I was hoping it was relevant to my issue. More importantly, I was misleading and wrong in trying to 'summarize' the docs, stating there are new and old methods. The examples in the patch say those two cases: select_stmt = select([User]).where(User.id == 7) q = session.query(User).select_entity_from(select_stmt) user_from_select = aliased(User, select_stmt.alias()) should produce similar result, i.e. give you User entity from different mapping then usual; whether select_from() should work as intended - resulting cartesian product in docs example should be 'eliminated' by further join. Cheers, a. -- 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?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
Re: [sqlalchemy] object has no attribute 'delete'
http://www.sqlalchemy.org/docs/ormtutorial.html#deleting On 13 April 2010 11:12, jo jose.soa...@sferacarta.com wrote: Hi all, I'm trying migrate from 0.3 to 0.6 I don't know how to delete an object in the old version it was: My.get(1).delete() in 0.6: My.get(1).delete() AttributeError: 'My' object has no attribute 'delete' -- 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] Re: Cannot delete SQLite '.db' using os.remove
Your example runs fine on Ubuntu 9.04, with python 2.6.2 and
SQLAlchemy-0.6beta1.
On 9 March 2010 05:49, Lynton Grice lyntongr...@gmail.com wrote:
Hi Michael,
Can you paste the following code into your editor and try it out? Can
you tell me what I would need to do to close the connections in this
case?
Any help would be greatly appreciated ;-)
from sqlalchemy import *
from sqlalchemy.orm import sessionmaker
from sqlalchemy.orm import mapper
from sqlalchemy.pool import StaticPool
import os
class Message(object):
pass
if __name__ == '__main__':
db_conn = 'sqlite:///foo.db'
db = create_engine(db_conn,echo=False, poolclass=StaticPool)
metadata = MetaData(db)
queueName = 'foo'
queue = Table(queueName, metadata,
Column('IDX', Integer, primary_key=True,
autoincrement = True ),
Column('ID', String(64)),
Column('CORRELATIONID', String(64)),)
queue.create()
session_maker = sessionmaker(bind=db)
session = session_maker()
mapper(Message, queue)
msg = Message()
msg.ID = '1234'
msg.CORRELATIONID = '111'
session.add(msg)
session.commit()
print Message count: + str(session.query(Message).count())
db.dispose()
os.remove('foo.db')
print Done...
Thanks
Lynton
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[sqlalchemy] Re: How to order_by relation by another join?
Thanks, Mike!
Your example indeed works, but unfortunately when I add inheritance,
mapper fails to generate proper (inherited) class:
(I've changed code a little, so it represents more what I'm trying to
do)
from sqlalchemy import *
from sqlalchemy.orm import *
from sqlalchemy.ext.declarative import declarative_base
engine = create_engine('sqlite://', echo=True)
Base = declarative_base()
class Detail(Base):
__tablename__ = 'detail'
id = Column(Integer, primary_key=True)
sort = Column(Integer)
class Order(Base):
__tablename__ = 'order'
id = Column(Integer, primary_key=True)
class Item(Base):
__tablename__ = 'item'
id = Column(Integer, primary_key=True)
order_id = Column(Integer, ForeignKey('order.id'))
detail_id = Column(Integer, ForeignKey('detail.id'))
detail = relation(Detail, uselist=False, lazy=False)
order = relation(Order, uselist=False)
type = Column(String(20))
__mapper_args__ = { 'polymorphic_on' : type}
class ValueItem(Item):
__mapper_args__ = { 'polymorphic_identity' : 'quantity' }
value = Column('quantity_value', Numeric(15, 4))
class ErrorItem(Item):
__mapper_args__ = { 'polymorphic_identity' : 'error' }
value = Column('error_value', String(15, 4))
Order.items = relation(Item)
j = Item.__table__.join(Detail.__table__)
itemdetail = mapper(Item, j, non_primary=True)
Order.sorteditems = relation(itemdetail,
order_by=Detail.__table__.c.sort, viewonly=True)
metadata = Base.metadata
metadata.create_all(engine)
Session = scoped_session(sessionmaker(bind=engine))
order = Order(id=1)
Session.add(order)
detail = Detail(id=1, sort=1)
order.items.append(ValueItem(id=1, detail=detail))
Session.commit()
for order in Session.query(Order).all():
for item in order.sorteditems:
print item
for item in order.items:
print item
...
__main__.Item object at 0x881ddac
__main__.ValueItem object at 0x960da6c
Am I making a obvious mistake somewhere here?
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Re: [sqlalchemy] Re: How to order_by relation by another join?
On 11 February 2010 14:26, Michael Bayer mike...@zzzcomputing.com wrote: I'm assuming these are single-table inheritance mappers (I forgot about that add the column trick..) So yeah my solution was a quick hack and to continue in this way you'd have to build non-primary mappers for each of ValueItem, ErrorItem that state inherits for the original non-primary mapper, using the polymorphic identities as well. It would still work. Thanks again! It's obvious now, of course. When I added other non-primary mappers, inheritance is working. I suppose declarative extension spoiled me... -- 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] How to order_by relation by another join?
Let's say I've got simple structure Order--Item--Detail.
class Detail(Base):
...
class Order(Base):
...
class Item(Base):
...
detail = relation(Detail, uselist=False, lazy=False)
order = relation(Order, uselist=False, backref='items')
Of course I can specify order_by for Order.items by any columns from
Item, but is there a way I can order_by a column defined in Detail?
I've naively tried something as backref('items', order_by=Detail.id),
but because Detail is anonymously joined to Item as e.g. 'details_1',
I've received ProgrammingError: invalid reference to FROM-clause
entry for table details.
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