[sqlalchemy] using sqlalchemy to track changes in database

Hi All, Can any body help me how Sqlalchemy can be used to identify changes in database? I mean how to identify that some rows got delete or added after particular time.? Thanks Balaji -- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To unsubsc

Re: [sqlalchemy] If path in joinedload() include self-referential relationship, should I alias() every table after that relation ?

On 7/15/15 4:40 PM, Юрий Пайков wrote: Ok, that is clear now. Eagerloading of tables occurring more than once in a query is a bit confusing for me as it is not well-documented, for example that *contains_eager()* needs *alias=* in order to work properly for a second occurrence of a table. If

Re: [sqlalchemy] strange behavior in count with custom mapper option

there's your two rows: Row (None, 24769797950537732L, datetime.datetime(2015, 7, 15, 17, 49, 57, 410290, tzinfo=psycopg2.tz.FixedOffsetTimezone(offset=-180, name=None)), datetime.datetime(2015, 7, 15, 17, 49, 57, 410305, tzinfo=psycopg2.tz.FixedOffsetTimezone(offset=-180, name=None)), 0L, 24

Re: [sqlalchemy] If path in joinedload() include self-referential relationship, should I alias() every table after that relation ?

Ok, that is clear now. Eagerloading of tables occurring more than once in a query is a bit confusing for me as it is not well-documented, for example that *contains_eager()* needs *alias=* in order to work properly for a second occurrence of a table. If I might I would advise you to shed some

Re: [sqlalchemy] strange behavior in count with custom mapper option

the interesting is, if i get the count() produced sql and put it into psql ... SELECT count(*) AS count_1 FROM system_unit, ( SELECT system_unit.fk_updated_by AS system_unit_fk_updated_by, system_unit.fk_created_by AS system_unit_fk_created_by, system_unit.dt_created_on AS system_

Re: [sqlalchemy] strange behavior in count with custom mapper option

right! sorry, now here we go (again): (Pdb) import logging (Pdb) logging.basicConfig() (Pdb) logging.getLogger('sqlalchemy.engine').setLevel(logging.DEBUG) (Pdb) session.query(MachineUnit).filter(MachineUnit.id_ == 24769797950537768).count() 2015-07-15 16:56:44,565 INFO sqlalch

Re: [sqlalchemy] strange behavior in count with custom mapper option

On 7/15/15 3:46 PM, Richard Gerd Kuesters wrote: thanks Mike! here we go: (Pdb) session.query(MachineUnit).filter(MachineUnit.id_ == 24769797950537768).count() 2015-07-15 16:43:53,114 INFO sqlalchemy.engine.base.Engine SELECT count(*) AS count_1 FROM system_unit, (SELECT s

Re: [sqlalchemy] strange behavior in count with custom mapper option

oh, the pk "24769797950537768" is a postgres biginteger. On 07/15/2015 04:46 PM, Richard Gerd Kuesters wrote: thanks Mike! here we go: (Pdb) session.query(MachineUnit).filter(MachineUnit.id_ == 24769797950537768).count() 2015-07-15 16:43:53,114 INFO sqlalchemy.engine.base.Engine S

Re: [sqlalchemy] strange behavior in count with custom mapper option

thanks Mike! here we go: (Pdb) session.query(MachineUnit).filter(MachineUnit.id_ == 24769797950537768).count() 2015-07-15 16:43:53,114 INFO sqlalchemy.engine.base.Engine SELECT count(*) AS count_1 FROM system_unit, (SELECT system_unit.fk_updated_by AS system_unit_fk_updated_by,

Re: [sqlalchemy] strange behavior in count with custom mapper option

On 7/15/15 3:13 PM, Richard Gerd Kuesters wrote: does this happen even with a filter for a PK? the problem is: >>> session.query(Entity).filter(Entity.id_ == 24769797950537768).count() == 2 >>> len(session.query(Entity).filter(Entity.id_ == 24769797950537768).all()) == 1 i don't see where

Re: [sqlalchemy] strange behavior in count with custom mapper option

does this happen even with a filter for a PK? the problem is: >>> session.query(Entity).filter(Entity.id_ == 24769797950537768).count() == 2 >>> len(session.query(Entity).filter(Entity.id_ == 24769797950537768).all()) == 1 i don't see where i have 2 pks with the same value ... in psql: mydb

Re: [sqlalchemy] strange behavior in count with custom mapper option

On 7/15/15 2:11 PM, Richard Gerd Kuesters wrote: hello! i'm encountering a weird behaviur with session.count() when using a custom mapper that implements a where condition to every session. first, what is happening: >>> len(session.query(Entity).all()) == 1 >>> session.query(Entity).count(

Re: [sqlalchemy] strange behavior in count with custom mapper option

oh, forgot to mention: * this occurs even with a filter that's supposed to bring one register only (at the database level it works); * in the database level, a count *without* the where clause brings the result i mentioned earlier. thanks, richard. On 07/15/2015 03:11 PM, Richard Gerd Kues

[sqlalchemy] strange behavior in count with custom mapper option

hello! i'm encountering a weird behaviur with session.count() when using a custom mapper that implements a where condition to every session. first, what is happening: >>> len(session.query(Entity).all()) == 1 >>> session.query(Entity).count() == 2 "Entity" is a base polymorphic entity, inher

Re: [sqlalchemy] If path in joinedload() include self-referential relationship, should I alias() every table after that relation ?

On 7/15/15 2:42 AM, Юрий Пайков wrote: I have an example here https://gist.github.com/ojomio/aa5eca3bea03d21e00e8. This code issue exactly one query and load everything at one time What I am asking about is line https://gist.github.com/ojomio/aa5eca3bea03d21e00e8#file-gistfile1-py-L65 If I

Re: [sqlalchemy] One-to-one relationship as a boolean flag

I thought maybe there was a simpler way to do that, but the hybrid_property works. Thanks. On Wed, Jul 8, 2015 at 11:19 AM, Mike Bayer wrote: > > > On 7/8/15 12:15 AM, Pedro Werneck wrote: > > > Let's say I have a table 'user', and for backwards compatibility reasons I > have a single-column tabl

Re: [sqlalchemy] is it two or more levels of polymorphism possible?

oh, yes, i was thinking about cascading polymorphic_on, like you mentioned. but, no problem, i'll try to workaround my problem with a more simple approach (the old soft-delete dilemma) ... thanks for your help, Mike! best regards, richard. On 07/15/2015 10:46 AM, Mike Bayer wrote: On 7/

Re: [sqlalchemy] is it two or more levels of polymorphism possible?

On 7/15/15 9:09 AM, Richard Gerd Kuesters wrote: hi all, i was wondering if there's a way to create more than one level of polymorphic entities in sa. quick example: class Foo(Base): ... __mapper_args__ = { ... } class Bar(Foo): ... __mapper_args__ =

[sqlalchemy] Re: How to jsonify Query result?

Ok, that approach isn't cool.. I get another one from flask_jsontools and it does what I need! json.dumps(q, cls=DynamicJSONEncoder) Base = declarative_base(cls=JsonSerializableBase) import decimal from datetime import datetime, date from json import JSONEncoder from sqlalchemy import inspe

[sqlalchemy] is it two or more levels of polymorphism possible?

hi all, i was wondering if there's a way to create more than one level of polymorphic entities in sa. quick example: class Foo(Base): ... __mapper_args__ = { ... } class Bar(Foo): ... __mapper_args__ = { ??? } # <--- polymorphic_identity for ... two?