Re: [sqlalchemy] Event do not fire on m2m relation
On Wed, Mar 20, 2019 at 7:54 AM Денис Ралко wrote:
>
> Sorry, my mistake
>
> Site.entity_id == MODEL_2.id
> And I solve my problem by change mapper.attrs -> mapper.column_attrs
>
> And now I want to ask you
> Can event directly set on Table colums?
events for changes of value need to be set for ORM level attributes.
If you can illustrate what you mean that might help.
>
> On Monday, March 18, 2019 at 10:28:54 PM UTC+2, Mike Bayer wrote:
>>
>> On Mon, Mar 18, 2019 at 11:07 AM Денис Ралко wrote:
>> >
>> > Thx for your quick answer.
>> > About second question
>> >
>> > I have event, for example
>> >
>> > def track_instances_before_flush(session, context, instances):
>> > for obj in chain(session.new, session.dirty):
>> > if session.is_modified(obj):
>> > print "Before Flush"
>> >
>> > table_name = obj.__class__.__dict__['__tablename__']
>> >
>> > print "Table_name ---", table_name
>> >
>> >
>> > print "Raw obj - ", obj
>> >
>> > state_before = {}
>> > state_after = {}
>> > mapper = inspect(obj)
>> > attrs = class_mapper(obj.__class__).column_attrs
>> >
>> > for attr in attrs:
>> > hist = mapper.attrs[attr.key].history
>> > if hist.has_changes():
>> > state_before[attr.key] = get_history(obj,
>> > attr.key)[2][0]
>> > state_after[attr.key] = getattr(obj, attr.key)
>> >
>> > print "BEFORE -", state_before
>> > print "AFTER -", state_after
>> >
>> >
>> >
>> > and register it by
>> >
>> > listen(app.db.session, 'before_flush', track_instances_before_flush)
>>
>> the code you've sent is still incomplete, for example i dont know what
>> "Site" is, but if you want to track relationships you need to look at
>> mapper.attrs or mapper.relationship_attrs.POC below with what I
>> could derive from your code fragments.
>>
>> from __future__ import print_function
>>
>> from itertools import chain
>>
>> from sqlalchemy import Column
>> from sqlalchemy import create_engine
>> from sqlalchemy import ForeignKey
>> from sqlalchemy import inspect
>> from sqlalchemy import Integer
>> from sqlalchemy import Table
>> from sqlalchemy import UniqueConstraint
>> from sqlalchemy.event import listen
>> from sqlalchemy.ext.declarative import declarative_base
>> from sqlalchemy.orm import class_mapper
>> from sqlalchemy.orm import relationship
>> from sqlalchemy.orm import Session
>>
>> Base = declarative_base()
>>
>>
>> class MODEL_1(Base):
>> __tablename__ = "MODEL_1"
>>
>> entity_id = Column(Integer, primary_key=True)
>>
>> # Don't know what "Site" is
>> # attr_1 = relationship(
>> #"MODEL_2",
>> #secondary="test2test",
>> #lazy="dynamic",
>> #primaryjoin="MODEL_1.id == test2test.c.first_id",
>> #secondaryjoin="test2test.c.second_id == Site.entity_id",
>> # )
>>
>>
>> class MODEL_2(Base):
>> __tablename__ = "MODEL_2"
>>
>> id = Column(Integer, primary_key=True)
>>
>> attr_2 = relationship("MODEL_1", secondary="test2test", lazy="dynamic")
>>
>>
>> t_ = Table(
>> "test2test",
>> Base.metadata,
>> Column(
>> "first_id", Integer, ForeignKey("MODEL_1.entity_id"), nullable=False
>> ),
>> Column("second_id", Integer, ForeignKey("MODEL_2.id"), nullable=False),
>> UniqueConstraint("first_id", "second_id", name="uq_test2test"),
>> )
>>
>> def track_instances_before_flush(session, context, instances):
>> for obj in chain(session.new, session.dirty):
>> if session.is_modified(obj):
>> print("Before Flush")
>>
>> table_name = obj.__class__.__dict__["__tablename__"]
>>
>> print("Table_name ---", table_name)
>>
>> print("Raw obj - ", obj)
>>
>> state_before = {}
>> state_after = {}
>> mapper = inspect(obj)
>> attrs = class_mapper(obj.__class__).attrs
>>
>> for attr in attrs:
>> hist = mapper.attrs[attr.key].history
>> if hist.has_changes():
>> state_before[attr.key] = hist[2] or hist[1]
>> state_after[attr.key] = hist[0]
>>
>> print("BEFORE -", state_before)
>> print("AFTER -", state_after)
>>
>>
>> e = create_engine("sqlite://", echo=True)
>> Base.metadata.create_all(e)
>>
>> s = Session(e)
>>
>> listen(s, "before_flush", track_instances_before_flush)
>>
>>
>> m1 = MODEL_1()
>> m2 = MODEL_2()
>>
>> s.add_all([m1, m2])
>> s.commit()
>> print("--")
>>
>> m2.attr_2.append(m1)
>>
>> s.commit()
>>
>>
>>
>>
>> >
>> >
>> > and in output i see
>> > Before Flush
>> > Table_name --- MODEL_1
>> > Raw obj - <'MODEL_1' id=2050>
>> >
>> > BEFORE - {}
>> > AFTER - {}
>> >
>> > In view I change only attr_1 for MODEL_1
>> >
>> > On Monday, March 18, 2019 at 4:48:00 PM UTC+2, Mike Bayer wrote:
>> >>
>> >> On Mon,
Re: [sqlalchemy] Event do not fire on m2m relation
Sorry, my mistake
Site.entity_id == MODEL_2.id
And I solve my problem by change mapper.attrs -> mapper.column_attrs
And now I want to ask you
Can event directly set on Table colums?
On Monday, March 18, 2019 at 10:28:54 PM UTC+2, Mike Bayer wrote:
>
> On Mon, Mar 18, 2019 at 11:07 AM Денис Ралко > wrote:
> >
> > Thx for your quick answer.
> > About second question
> >
> > I have event, for example
> >
> > def track_instances_before_flush(session, context, instances):
> > for obj in chain(session.new, session.dirty):
> > if session.is_modified(obj):
> > print "Before Flush"
> >
> > table_name = obj.__class__.__dict__['__tablename__']
> >
> > print "Table_name ---", table_name
> >
> >
> > print "Raw obj - ", obj
> >
> > state_before = {}
> > state_after = {}
> > mapper = inspect(obj)
> > attrs = class_mapper(obj.__class__).column_attrs
> >
> > for attr in attrs:
> > hist = mapper.attrs[attr.key].history
> > if hist.has_changes():
> > state_before[attr.key] = get_history(obj,
> attr.key)[2][0]
> > state_after[attr.key] = getattr(obj, attr.key)
> >
> > print "BEFORE -", state_before
> > print "AFTER -", state_after
> >
> >
> >
> > and register it by
> >
> > listen(app.db.session, 'before_flush', track_instances_before_flush)
>
> the code you've sent is still incomplete, for example i dont know what
> "Site" is, but if you want to track relationships you need to look at
> mapper.attrs or mapper.relationship_attrs.POC below with what I
> could derive from your code fragments.
>
> from __future__ import print_function
>
> from itertools import chain
>
> from sqlalchemy import Column
> from sqlalchemy import create_engine
> from sqlalchemy import ForeignKey
> from sqlalchemy import inspect
> from sqlalchemy import Integer
> from sqlalchemy import Table
> from sqlalchemy import UniqueConstraint
> from sqlalchemy.event import listen
> from sqlalchemy.ext.declarative import declarative_base
> from sqlalchemy.orm import class_mapper
> from sqlalchemy.orm import relationship
> from sqlalchemy.orm import Session
>
> Base = declarative_base()
>
>
> class MODEL_1(Base):
> __tablename__ = "MODEL_1"
>
> entity_id = Column(Integer, primary_key=True)
>
> # Don't know what "Site" is
> # attr_1 = relationship(
> #"MODEL_2",
> #secondary="test2test",
> #lazy="dynamic",
> #primaryjoin="MODEL_1.id == test2test.c.first_id",
> #secondaryjoin="test2test.c.second_id == Site.entity_id",
> # )
>
>
> class MODEL_2(Base):
> __tablename__ = "MODEL_2"
>
> id = Column(Integer, primary_key=True)
>
> attr_2 = relationship("MODEL_1", secondary="test2test",
> lazy="dynamic")
>
>
> t_ = Table(
> "test2test",
> Base.metadata,
> Column(
> "first_id", Integer, ForeignKey("MODEL_1.entity_id"),
> nullable=False
> ),
> Column("second_id", Integer, ForeignKey("MODEL_2.id"),
> nullable=False),
> UniqueConstraint("first_id", "second_id", name="uq_test2test"),
> )
>
> def track_instances_before_flush(session, context, instances):
> for obj in chain(session.new, session.dirty):
> if session.is_modified(obj):
> print("Before Flush")
>
> table_name = obj.__class__.__dict__["__tablename__"]
>
> print("Table_name ---", table_name)
>
> print("Raw obj - ", obj)
>
> state_before = {}
> state_after = {}
> mapper = inspect(obj)
> attrs = class_mapper(obj.__class__).attrs
>
> for attr in attrs:
> hist = mapper.attrs[attr.key].history
> if hist.has_changes():
> state_before[attr.key] = hist[2] or hist[1]
> state_after[attr.key] = hist[0]
>
> print("BEFORE -", state_before)
> print("AFTER -", state_after)
>
>
> e = create_engine("sqlite://", echo=True)
> Base.metadata.create_all(e)
>
> s = Session(e)
>
> listen(s, "before_flush", track_instances_before_flush)
>
>
> m1 = MODEL_1()
> m2 = MODEL_2()
>
> s.add_all([m1, m2])
> s.commit()
> print("--")
>
> m2.attr_2.append(m1)
>
> s.commit()
>
>
>
>
> >
> >
> > and in output i see
> > Before Flush
> > Table_name --- MODEL_1
> > Raw obj - <'MODEL_1' id=2050>
> >
> > BEFORE - {}
> > AFTER - {}
> >
> > In view I change only attr_1 for MODEL_1
> >
> > On Monday, March 18, 2019 at 4:48:00 PM UTC+2, Mike Bayer wrote:
> >>
> >> On Mon, Mar 18, 2019 at 10:30 AM Денис Ралко wrote:
> >> >
> >> > Hi, I have some issue
> >> >
> >> > I try implement track logic
> >> > I have 2 Models and connecting Table
> >> >
> >> > My first class
> >> >
> >> >
Re: [sqlalchemy] Event do not fire on m2m relation
On Mon, Mar 18, 2019 at 11:07 AM Денис Ралко wrote:
>
> Thx for your quick answer.
> About second question
>
> I have event, for example
>
> def track_instances_before_flush(session, context, instances):
> for obj in chain(session.new, session.dirty):
> if session.is_modified(obj):
> print "Before Flush"
>
> table_name = obj.__class__.__dict__['__tablename__']
>
> print "Table_name ---", table_name
>
>
> print "Raw obj - ", obj
>
> state_before = {}
> state_after = {}
> mapper = inspect(obj)
> attrs = class_mapper(obj.__class__).column_attrs
>
> for attr in attrs:
> hist = mapper.attrs[attr.key].history
> if hist.has_changes():
> state_before[attr.key] = get_history(obj, attr.key)[2][0]
> state_after[attr.key] = getattr(obj, attr.key)
>
> print "BEFORE -", state_before
> print "AFTER -", state_after
>
>
>
> and register it by
>
> listen(app.db.session, 'before_flush', track_instances_before_flush)
the code you've sent is still incomplete, for example i dont know what
"Site" is, but if you want to track relationships you need to look at
mapper.attrs or mapper.relationship_attrs.POC below with what I
could derive from your code fragments.
from __future__ import print_function
from itertools import chain
from sqlalchemy import Column
from sqlalchemy import create_engine
from sqlalchemy import ForeignKey
from sqlalchemy import inspect
from sqlalchemy import Integer
from sqlalchemy import Table
from sqlalchemy import UniqueConstraint
from sqlalchemy.event import listen
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import class_mapper
from sqlalchemy.orm import relationship
from sqlalchemy.orm import Session
Base = declarative_base()
class MODEL_1(Base):
__tablename__ = "MODEL_1"
entity_id = Column(Integer, primary_key=True)
# Don't know what "Site" is
# attr_1 = relationship(
#"MODEL_2",
#secondary="test2test",
#lazy="dynamic",
#primaryjoin="MODEL_1.id == test2test.c.first_id",
#secondaryjoin="test2test.c.second_id == Site.entity_id",
# )
class MODEL_2(Base):
__tablename__ = "MODEL_2"
id = Column(Integer, primary_key=True)
attr_2 = relationship("MODEL_1", secondary="test2test", lazy="dynamic")
t_ = Table(
"test2test",
Base.metadata,
Column(
"first_id", Integer, ForeignKey("MODEL_1.entity_id"), nullable=False
),
Column("second_id", Integer, ForeignKey("MODEL_2.id"), nullable=False),
UniqueConstraint("first_id", "second_id", name="uq_test2test"),
)
def track_instances_before_flush(session, context, instances):
for obj in chain(session.new, session.dirty):
if session.is_modified(obj):
print("Before Flush")
table_name = obj.__class__.__dict__["__tablename__"]
print("Table_name ---", table_name)
print("Raw obj - ", obj)
state_before = {}
state_after = {}
mapper = inspect(obj)
attrs = class_mapper(obj.__class__).attrs
for attr in attrs:
hist = mapper.attrs[attr.key].history
if hist.has_changes():
state_before[attr.key] = hist[2] or hist[1]
state_after[attr.key] = hist[0]
print("BEFORE -", state_before)
print("AFTER -", state_after)
e = create_engine("sqlite://", echo=True)
Base.metadata.create_all(e)
s = Session(e)
listen(s, "before_flush", track_instances_before_flush)
m1 = MODEL_1()
m2 = MODEL_2()
s.add_all([m1, m2])
s.commit()
print("--")
m2.attr_2.append(m1)
s.commit()
>
>
> and in output i see
> Before Flush
> Table_name --- MODEL_1
> Raw obj - <'MODEL_1' id=2050>
>
> BEFORE - {}
> AFTER - {}
>
> In view I change only attr_1 for MODEL_1
>
> On Monday, March 18, 2019 at 4:48:00 PM UTC+2, Mike Bayer wrote:
>>
>> On Mon, Mar 18, 2019 at 10:30 AM Денис Ралко wrote:
>> >
>> > Hi, I have some issue
>> >
>> > I try implement track logic
>> > I have 2 Models and connecting Table
>> >
>> > My first class
>> >
>> > class MODEL_1(object):
>> > # some values
>> >
>> > # relations:
>> > attr_1 = db.relationship('MODEL_2',
>> >secondary="test2test",
>> >lazy='dynamic',
>> >primaryjoin="MODEL_1.id ==
>> > test2test.c.first_id",
>> >secondaryjoin='test2test.c.second_id ==
>> > Site.entity_id')
>> >
>> > Second class
>> >
>> > class MODEL_2(object):
>> > # some values
>> > attr_2 = db.relationship('MODEL_1', secondary='test2test',
>> > lazy='dynamic')
>> >
>> >
>> > And relation table
>> >
>> >
>> > t_ = db.Table(
>> > 'test2test',
>> > db.Model.metadata,
>> >
>> >
Re: [sqlalchemy] Event do not fire on m2m relation
Thx for your quick answer.
About second question
I have event, for example
def track_instances_before_flush(session, context, instances):
for obj in chain(session.new, session.dirty):
if session.is_modified(obj):
print "Before Flush"
table_name = obj.__class__.__dict__['__tablename__']
print "Table_name ---", table_name
print "Raw obj - ", obj
state_before = {}
state_after = {}
mapper = inspect(obj)
attrs = class_mapper(obj.__class__).column_attrs
for attr in attrs:
hist = mapper.attrs[attr.key].history
if hist.has_changes():
state_before[attr.key] = get_history(obj, attr.key)[2][0]
state_after[attr.key] = getattr(obj, attr.key)
print "BEFORE -", state_before
print "AFTER -", state_after
and register it by
listen(app.db.session, 'before_flush', track_instances_before_flush)
and in output i see
Before Flush
Table_name --- MODEL_1
Raw obj - <'MODEL_1' id=2050>
BEFORE - {}
AFTER - {}
In view I change only attr_1 for MODEL_1
On Monday, March 18, 2019 at 4:48:00 PM UTC+2, Mike Bayer wrote:
>
> On Mon, Mar 18, 2019 at 10:30 AM Денис Ралко > wrote:
> >
> > Hi, I have some issue
> >
> > I try implement track logic
> > I have 2 Models and connecting Table
> >
> > My first class
> >
> > class MODEL_1(object):
> > # some values
> >
> > # relations:
> > attr_1 = db.relationship('MODEL_2',
> >secondary="test2test",
> >lazy='dynamic',
> >primaryjoin="MODEL_1.id ==
> test2test.c.first_id",
> >secondaryjoin='test2test.c.second_id ==
> Site.entity_id')
> >
> > Second class
> >
> > class MODEL_2(object):
> > # some values
> > attr_2 = db.relationship('MODEL_1', secondary='test2test',
> lazy='dynamic')
> >
> >
> > And relation table
> >
> >
> > t_ = db.Table(
> > 'test2test',
> > db.Model.metadata,
> >
> > db.Column('first_id', db.Integer,
> > db.ForeignKey('MODEL_1.entity_id'),
> > nullable=False),
> > db.Column('second_id', db.Integer,
> > db.ForeignKey('MODEL_2.id'),
> > nullable=False),
> > db.UniqueConstraint('first_id', 'second_id', name='uq_test2test')
> > )
> >
> >
> > I have some questions
> >
> > 1. can i do some table event what will fire, when will change some
> values in t_ table ?
>
> via the relationship, sure, use @validates or AttributeEvents for
> MODEL_1.attr1, MODEL_2.attr2
>
>
> https://docs.sqlalchemy.org/en/latest/orm/events.html?highlight=attributeevents#sqlalchemy.orm.events.AttributeEvents
>
>
>
> >
> > 2. if i set before_flush event and change some in MODEL_1, event fire,
> but session have no modified objects
>
> you would need to send along a complete example illustrating what you're
> doing.
>
>
>
> >
> > --
> > SQLAlchemy -
> > The Python SQL Toolkit and Object Relational Mapper
> >
> > http://www.sqlalchemy.org/
> >
> > To post example code, please provide an MCVE: Minimal, Complete, and
> Verifiable Example. See http://stackoverflow.com/help/mcve for a full
> description.
> > ---
> > 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+...@googlegroups.com .
> > To post to this group, send email to sqlal...@googlegroups.com
> .
> > Visit this group at https://groups.google.com/group/sqlalchemy.
> > For more options, visit https://groups.google.com/d/optout.
>
--
SQLAlchemy -
The Python SQL Toolkit and Object Relational Mapper
http://www.sqlalchemy.org/
To post example code, please provide an MCVE: Minimal, Complete, and Verifiable
Example. See http://stackoverflow.com/help/mcve for a full description.
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Re: [sqlalchemy] Event do not fire on m2m relation
On Mon, Mar 18, 2019 at 10:30 AM Денис Ралко wrote:
>
> Hi, I have some issue
>
> I try implement track logic
> I have 2 Models and connecting Table
>
> My first class
>
> class MODEL_1(object):
> # some values
>
> # relations:
> attr_1 = db.relationship('MODEL_2',
>secondary="test2test",
>lazy='dynamic',
>primaryjoin="MODEL_1.id == test2test.c.first_id",
>secondaryjoin='test2test.c.second_id ==
> Site.entity_id')
>
> Second class
>
> class MODEL_2(object):
> # some values
> attr_2 = db.relationship('MODEL_1', secondary='test2test', lazy='dynamic')
>
>
> And relation table
>
>
> t_ = db.Table(
> 'test2test',
> db.Model.metadata,
>
> db.Column('first_id', db.Integer,
> db.ForeignKey('MODEL_1.entity_id'),
> nullable=False),
> db.Column('second_id', db.Integer,
> db.ForeignKey('MODEL_2.id'),
> nullable=False),
> db.UniqueConstraint('first_id', 'second_id', name='uq_test2test')
> )
>
>
> I have some questions
>
> 1. can i do some table event what will fire, when will change some values in
> t_ table ?
via the relationship, sure, use @validates or AttributeEvents for
MODEL_1.attr1, MODEL_2.attr2
https://docs.sqlalchemy.org/en/latest/orm/events.html?highlight=attributeevents#sqlalchemy.orm.events.AttributeEvents
>
> 2. if i set before_flush event and change some in MODEL_1, event fire, but
> session have no modified objects
you would need to send along a complete example illustrating what you're doing.
>
> --
> SQLAlchemy -
> The Python SQL Toolkit and Object Relational Mapper
>
> http://www.sqlalchemy.org/
>
> To post example code, please provide an MCVE: Minimal, Complete, and
> Verifiable Example. See http://stackoverflow.com/help/mcve for a full
> description.
> ---
> 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 https://groups.google.com/group/sqlalchemy.
> For more options, visit https://groups.google.com/d/optout.
--
SQLAlchemy -
The Python SQL Toolkit and Object Relational Mapper
http://www.sqlalchemy.org/
To post example code, please provide an MCVE: Minimal, Complete, and Verifiable
Example. See http://stackoverflow.com/help/mcve for a full description.
---
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[sqlalchemy] Event do not fire on m2m relation
Hi, I have some issue
I try implement track logic
I have 2 Models and connecting Table
My first class
class MODEL_1(object):
# some values
# relations:
attr_1 = db.relationship('MODEL_2',
secondary="test2test",
lazy='dynamic',
primaryjoin="MODEL_1.id == test2test.c.first_id",
secondaryjoin='test2test.c.second_id ==
Site.entity_id')
Second class
class MODEL_2(object):
# some values
attr_2 = db.relationship('MODEL_1', secondary='test2test', lazy='dynamic')
And relation table
t_ = db.Table(
'test2test',
db.Model.metadata,
db.Column('first_id', db.Integer,
db.ForeignKey('MODEL_1.entity_id'),
nullable=False),
db.Column('second_id', db.Integer,
db.ForeignKey('MODEL_2.id'),
nullable=False),
db.UniqueConstraint('first_id', 'second_id', name='uq_test2test')
)
I have some questions
1. can i do some table event what will fire, when will change some values in t_
table ?
2. if i set before_flush event and change some in MODEL_1, event fire, but
session have no modified objects
--
SQLAlchemy -
The Python SQL Toolkit and Object Relational Mapper
http://www.sqlalchemy.org/
To post example code, please provide an MCVE: Minimal, Complete, and Verifiable
Example. See http://stackoverflow.com/help/mcve for a full description.
---
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