Get sqlalchemy base class object instead of children





.everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty,.everyoneloves__bot-mid-leaderboard:empty{ height:90px;width:728px;box-sizing:border-box;
}







7















I have three classes in my model, which one class inherited by the other two:



class Item(Base):
__tablename__ = 'item'

id = Column(Integer, primary_key=True)
title = Column(Unicode(300))
type = Column(Unicode(50))

__mapper_args__ = {
'polymorphic_on': type
}


class Note(Item):
__tablename__ = 'note'

id = Column(Integer, ForeignKey('item.id'), primary_key=True)
extra = Column(Text)

__mapper_args__ = {
'polymorphic_identity': 'note'
}


class Task(Item):
__tablename__ = 'task'

id = Column(Integer, ForeignKey('item.id'), primary_key=True)
another_extra = Column(Text)

__mapper_args__ = {
'polymorphic_identity': 'task'
}


So, when I execute session.query(Item).all() I get a list that includes both Note and Task objects, but I don't want that, I want my objects to be the instance of Item class and just have id, title, type, not those extra fields. how should I write the query?



to clarify more, currently, I get:



[
<models.Note object at 0x7f25ac3ffe80>,
<models.Task object at 0x7f25ac3ffe80>,
<models.Task object at 0x7f25ac3ffe80>,
...
]


But I want to get:



[
<models.Item object at 0x000000000000>,
<models.Item object at 0x000000000000>,
<models.Item object at 0x000000000000>,
...
]









share|improve this question

























  • Would it be enough to just query for those specific columns and get a named tuple back? Or do you absolutely need to receive an Item type back?

    – SuperShoot
    Nov 24 '18 at 12:57











  • @SuperShoot I need them to be an instance of Item class. Thanks for the like by the way.

    – Mehrdad Pedramfar
    Nov 24 '18 at 12:59











  • Not sure if it will help you, but I noticed that if you remove the polymorphic identities it works as you expect.

    – Hans Bouwmeester
    Nov 24 '18 at 16:07











  • The code doesn't run for me (getting: "No such polymorphic_identity 'type' is defined")(?) but per the docs I think just_item = with_polymorphic(Item, [Note, Task]) then followed by: session.query(just_item).all() may work? See: docs.sqlalchemy.org/en/latest/orm/inheritance_loading.html

    – Hans Bouwmeester
    Nov 24 '18 at 16:38













  • @HansBouwmeester with_polymorphic(Item, [Note, Task]) ensures that when querying on the base class, the attributes belonging to the the list of classes (Note and Task in this example) are eager loaded so that the resultant objects will not have to lazy load attribute values later. The objects returned from that query will still be Note and Task objects.

    – SuperShoot
    Nov 24 '18 at 21:59




















7















I have three classes in my model, which one class inherited by the other two:



class Item(Base):
__tablename__ = 'item'

id = Column(Integer, primary_key=True)
title = Column(Unicode(300))
type = Column(Unicode(50))

__mapper_args__ = {
'polymorphic_on': type
}


class Note(Item):
__tablename__ = 'note'

id = Column(Integer, ForeignKey('item.id'), primary_key=True)
extra = Column(Text)

__mapper_args__ = {
'polymorphic_identity': 'note'
}


class Task(Item):
__tablename__ = 'task'

id = Column(Integer, ForeignKey('item.id'), primary_key=True)
another_extra = Column(Text)

__mapper_args__ = {
'polymorphic_identity': 'task'
}


So, when I execute session.query(Item).all() I get a list that includes both Note and Task objects, but I don't want that, I want my objects to be the instance of Item class and just have id, title, type, not those extra fields. how should I write the query?



to clarify more, currently, I get:



[
<models.Note object at 0x7f25ac3ffe80>,
<models.Task object at 0x7f25ac3ffe80>,
<models.Task object at 0x7f25ac3ffe80>,
...
]


But I want to get:



[
<models.Item object at 0x000000000000>,
<models.Item object at 0x000000000000>,
<models.Item object at 0x000000000000>,
...
]









share|improve this question

























  • Would it be enough to just query for those specific columns and get a named tuple back? Or do you absolutely need to receive an Item type back?

    – SuperShoot
    Nov 24 '18 at 12:57











  • @SuperShoot I need them to be an instance of Item class. Thanks for the like by the way.

    – Mehrdad Pedramfar
    Nov 24 '18 at 12:59











  • Not sure if it will help you, but I noticed that if you remove the polymorphic identities it works as you expect.

    – Hans Bouwmeester
    Nov 24 '18 at 16:07











  • The code doesn't run for me (getting: "No such polymorphic_identity 'type' is defined")(?) but per the docs I think just_item = with_polymorphic(Item, [Note, Task]) then followed by: session.query(just_item).all() may work? See: docs.sqlalchemy.org/en/latest/orm/inheritance_loading.html

    – Hans Bouwmeester
    Nov 24 '18 at 16:38













  • @HansBouwmeester with_polymorphic(Item, [Note, Task]) ensures that when querying on the base class, the attributes belonging to the the list of classes (Note and Task in this example) are eager loaded so that the resultant objects will not have to lazy load attribute values later. The objects returned from that query will still be Note and Task objects.

    – SuperShoot
    Nov 24 '18 at 21:59
















7












7








7


1






I have three classes in my model, which one class inherited by the other two:



class Item(Base):
__tablename__ = 'item'

id = Column(Integer, primary_key=True)
title = Column(Unicode(300))
type = Column(Unicode(50))

__mapper_args__ = {
'polymorphic_on': type
}


class Note(Item):
__tablename__ = 'note'

id = Column(Integer, ForeignKey('item.id'), primary_key=True)
extra = Column(Text)

__mapper_args__ = {
'polymorphic_identity': 'note'
}


class Task(Item):
__tablename__ = 'task'

id = Column(Integer, ForeignKey('item.id'), primary_key=True)
another_extra = Column(Text)

__mapper_args__ = {
'polymorphic_identity': 'task'
}


So, when I execute session.query(Item).all() I get a list that includes both Note and Task objects, but I don't want that, I want my objects to be the instance of Item class and just have id, title, type, not those extra fields. how should I write the query?



to clarify more, currently, I get:



[
<models.Note object at 0x7f25ac3ffe80>,
<models.Task object at 0x7f25ac3ffe80>,
<models.Task object at 0x7f25ac3ffe80>,
...
]


But I want to get:



[
<models.Item object at 0x000000000000>,
<models.Item object at 0x000000000000>,
<models.Item object at 0x000000000000>,
...
]









share|improve this question
















I have three classes in my model, which one class inherited by the other two:



class Item(Base):
__tablename__ = 'item'

id = Column(Integer, primary_key=True)
title = Column(Unicode(300))
type = Column(Unicode(50))

__mapper_args__ = {
'polymorphic_on': type
}


class Note(Item):
__tablename__ = 'note'

id = Column(Integer, ForeignKey('item.id'), primary_key=True)
extra = Column(Text)

__mapper_args__ = {
'polymorphic_identity': 'note'
}


class Task(Item):
__tablename__ = 'task'

id = Column(Integer, ForeignKey('item.id'), primary_key=True)
another_extra = Column(Text)

__mapper_args__ = {
'polymorphic_identity': 'task'
}


So, when I execute session.query(Item).all() I get a list that includes both Note and Task objects, but I don't want that, I want my objects to be the instance of Item class and just have id, title, type, not those extra fields. how should I write the query?



to clarify more, currently, I get:



[
<models.Note object at 0x7f25ac3ffe80>,
<models.Task object at 0x7f25ac3ffe80>,
<models.Task object at 0x7f25ac3ffe80>,
...
]


But I want to get:



[
<models.Item object at 0x000000000000>,
<models.Item object at 0x000000000000>,
<models.Item object at 0x000000000000>,
...
]






python python-3.x inheritance sqlalchemy






share|improve this question















share|improve this question













share|improve this question




share|improve this question








edited Nov 26 '18 at 5:53







Mehrdad Pedramfar

















asked Nov 24 '18 at 12:10









Mehrdad PedramfarMehrdad Pedramfar

6,55311644




6,55311644













  • Would it be enough to just query for those specific columns and get a named tuple back? Or do you absolutely need to receive an Item type back?

    – SuperShoot
    Nov 24 '18 at 12:57











  • @SuperShoot I need them to be an instance of Item class. Thanks for the like by the way.

    – Mehrdad Pedramfar
    Nov 24 '18 at 12:59











  • Not sure if it will help you, but I noticed that if you remove the polymorphic identities it works as you expect.

    – Hans Bouwmeester
    Nov 24 '18 at 16:07











  • The code doesn't run for me (getting: "No such polymorphic_identity 'type' is defined")(?) but per the docs I think just_item = with_polymorphic(Item, [Note, Task]) then followed by: session.query(just_item).all() may work? See: docs.sqlalchemy.org/en/latest/orm/inheritance_loading.html

    – Hans Bouwmeester
    Nov 24 '18 at 16:38













  • @HansBouwmeester with_polymorphic(Item, [Note, Task]) ensures that when querying on the base class, the attributes belonging to the the list of classes (Note and Task in this example) are eager loaded so that the resultant objects will not have to lazy load attribute values later. The objects returned from that query will still be Note and Task objects.

    – SuperShoot
    Nov 24 '18 at 21:59





















  • Would it be enough to just query for those specific columns and get a named tuple back? Or do you absolutely need to receive an Item type back?

    – SuperShoot
    Nov 24 '18 at 12:57











  • @SuperShoot I need them to be an instance of Item class. Thanks for the like by the way.

    – Mehrdad Pedramfar
    Nov 24 '18 at 12:59











  • Not sure if it will help you, but I noticed that if you remove the polymorphic identities it works as you expect.

    – Hans Bouwmeester
    Nov 24 '18 at 16:07











  • The code doesn't run for me (getting: "No such polymorphic_identity 'type' is defined")(?) but per the docs I think just_item = with_polymorphic(Item, [Note, Task]) then followed by: session.query(just_item).all() may work? See: docs.sqlalchemy.org/en/latest/orm/inheritance_loading.html

    – Hans Bouwmeester
    Nov 24 '18 at 16:38













  • @HansBouwmeester with_polymorphic(Item, [Note, Task]) ensures that when querying on the base class, the attributes belonging to the the list of classes (Note and Task in this example) are eager loaded so that the resultant objects will not have to lazy load attribute values later. The objects returned from that query will still be Note and Task objects.

    – SuperShoot
    Nov 24 '18 at 21:59



















Would it be enough to just query for those specific columns and get a named tuple back? Or do you absolutely need to receive an Item type back?

– SuperShoot
Nov 24 '18 at 12:57





Would it be enough to just query for those specific columns and get a named tuple back? Or do you absolutely need to receive an Item type back?

– SuperShoot
Nov 24 '18 at 12:57













@SuperShoot I need them to be an instance of Item class. Thanks for the like by the way.

– Mehrdad Pedramfar
Nov 24 '18 at 12:59





@SuperShoot I need them to be an instance of Item class. Thanks for the like by the way.

– Mehrdad Pedramfar
Nov 24 '18 at 12:59













Not sure if it will help you, but I noticed that if you remove the polymorphic identities it works as you expect.

– Hans Bouwmeester
Nov 24 '18 at 16:07





Not sure if it will help you, but I noticed that if you remove the polymorphic identities it works as you expect.

– Hans Bouwmeester
Nov 24 '18 at 16:07













The code doesn't run for me (getting: "No such polymorphic_identity 'type' is defined")(?) but per the docs I think just_item = with_polymorphic(Item, [Note, Task]) then followed by: session.query(just_item).all() may work? See: docs.sqlalchemy.org/en/latest/orm/inheritance_loading.html

– Hans Bouwmeester
Nov 24 '18 at 16:38







The code doesn't run for me (getting: "No such polymorphic_identity 'type' is defined")(?) but per the docs I think just_item = with_polymorphic(Item, [Note, Task]) then followed by: session.query(just_item).all() may work? See: docs.sqlalchemy.org/en/latest/orm/inheritance_loading.html

– Hans Bouwmeester
Nov 24 '18 at 16:38















@HansBouwmeester with_polymorphic(Item, [Note, Task]) ensures that when querying on the base class, the attributes belonging to the the list of classes (Note and Task in this example) are eager loaded so that the resultant objects will not have to lazy load attribute values later. The objects returned from that query will still be Note and Task objects.

– SuperShoot
Nov 24 '18 at 21:59







@HansBouwmeester with_polymorphic(Item, [Note, Task]) ensures that when querying on the base class, the attributes belonging to the the list of classes (Note and Task in this example) are eager loaded so that the resultant objects will not have to lazy load attribute values later. The objects returned from that query will still be Note and Task objects.

– SuperShoot
Nov 24 '18 at 21:59














1 Answer
1






active

oldest

votes


















1














NOTE: This may be problematic in a multi-threaded application.



You could use a context manager to temporarily block the polymorphism:



from contextlib import contextmanager
from sqlalchemy import inspect

@contextmanager
def no_poly(class_):
mapper = inspect(class_).mapper
polycol = mapper.polymorphic_on
mapper.polymorphic_on = None
yield class_
mapper.polymorphic_on = polycol

Base.metadata.drop_all(engine)
Base.metadata.create_all(engine)
task = Task(title='Task Title', another_extra='something')
s = Session()
s.add(task)
s.commit()

# opening a new session as if the pk already exists in the
# identity map it will return whatever type that pk is
# pointing at.
s = Session()
with no_poly(Item) as class_:
inst = s.query(class_).all()
print(inst) # [<__main__.Item object at 0x000001443685DDD8>]
s = Session() # new session again.
inst = s.query(Item).all()
print(inst) # [<__main__.Task object at 0x00000144368770B8>]


Something to be mindful of and as noted in the comments in my example, if the identity of the object is already referenced in the Identity Map, then you will get back whatever type is held in there, regardless of the class that you query on.






share|improve this answer





















  • 3





    This seems like it might pose some risks in multithreaded programs, since it modifies the mapper in place.

    – Ilja Everilä
    Nov 26 '18 at 5:48











  • IIja is correct, I don't really want to modify mapper, I was just looking for a query or __mapper_args__ to work somehow.

    – Mehrdad Pedramfar
    Nov 26 '18 at 6:01











  • @IljaEverilä do you have any idea about how to achive this?

    – Mehrdad Pedramfar
    Nov 26 '18 at 6:02











  • Yeh, it's not threadsafe. I'll note that in the answer. Is that a prerequisite in this case?

    – SuperShoot
    Nov 26 '18 at 6:29












Your Answer






StackExchange.ifUsing("editor", function () {
StackExchange.using("externalEditor", function () {
StackExchange.using("snippets", function () {
StackExchange.snippets.init();
});
});
}, "code-snippets");

StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "1"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});

function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});


}
});














draft saved

draft discarded


















StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53458005%2fget-sqlalchemy-base-class-object-instead-of-children%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown

























1 Answer
1






active

oldest

votes








1 Answer
1






active

oldest

votes









active

oldest

votes






active

oldest

votes









1














NOTE: This may be problematic in a multi-threaded application.



You could use a context manager to temporarily block the polymorphism:



from contextlib import contextmanager
from sqlalchemy import inspect

@contextmanager
def no_poly(class_):
mapper = inspect(class_).mapper
polycol = mapper.polymorphic_on
mapper.polymorphic_on = None
yield class_
mapper.polymorphic_on = polycol

Base.metadata.drop_all(engine)
Base.metadata.create_all(engine)
task = Task(title='Task Title', another_extra='something')
s = Session()
s.add(task)
s.commit()

# opening a new session as if the pk already exists in the
# identity map it will return whatever type that pk is
# pointing at.
s = Session()
with no_poly(Item) as class_:
inst = s.query(class_).all()
print(inst) # [<__main__.Item object at 0x000001443685DDD8>]
s = Session() # new session again.
inst = s.query(Item).all()
print(inst) # [<__main__.Task object at 0x00000144368770B8>]


Something to be mindful of and as noted in the comments in my example, if the identity of the object is already referenced in the Identity Map, then you will get back whatever type is held in there, regardless of the class that you query on.






share|improve this answer





















  • 3





    This seems like it might pose some risks in multithreaded programs, since it modifies the mapper in place.

    – Ilja Everilä
    Nov 26 '18 at 5:48











  • IIja is correct, I don't really want to modify mapper, I was just looking for a query or __mapper_args__ to work somehow.

    – Mehrdad Pedramfar
    Nov 26 '18 at 6:01











  • @IljaEverilä do you have any idea about how to achive this?

    – Mehrdad Pedramfar
    Nov 26 '18 at 6:02











  • Yeh, it's not threadsafe. I'll note that in the answer. Is that a prerequisite in this case?

    – SuperShoot
    Nov 26 '18 at 6:29
















1














NOTE: This may be problematic in a multi-threaded application.



You could use a context manager to temporarily block the polymorphism:



from contextlib import contextmanager
from sqlalchemy import inspect

@contextmanager
def no_poly(class_):
mapper = inspect(class_).mapper
polycol = mapper.polymorphic_on
mapper.polymorphic_on = None
yield class_
mapper.polymorphic_on = polycol

Base.metadata.drop_all(engine)
Base.metadata.create_all(engine)
task = Task(title='Task Title', another_extra='something')
s = Session()
s.add(task)
s.commit()

# opening a new session as if the pk already exists in the
# identity map it will return whatever type that pk is
# pointing at.
s = Session()
with no_poly(Item) as class_:
inst = s.query(class_).all()
print(inst) # [<__main__.Item object at 0x000001443685DDD8>]
s = Session() # new session again.
inst = s.query(Item).all()
print(inst) # [<__main__.Task object at 0x00000144368770B8>]


Something to be mindful of and as noted in the comments in my example, if the identity of the object is already referenced in the Identity Map, then you will get back whatever type is held in there, regardless of the class that you query on.






share|improve this answer





















  • 3





    This seems like it might pose some risks in multithreaded programs, since it modifies the mapper in place.

    – Ilja Everilä
    Nov 26 '18 at 5:48











  • IIja is correct, I don't really want to modify mapper, I was just looking for a query or __mapper_args__ to work somehow.

    – Mehrdad Pedramfar
    Nov 26 '18 at 6:01











  • @IljaEverilä do you have any idea about how to achive this?

    – Mehrdad Pedramfar
    Nov 26 '18 at 6:02











  • Yeh, it's not threadsafe. I'll note that in the answer. Is that a prerequisite in this case?

    – SuperShoot
    Nov 26 '18 at 6:29














1












1








1







NOTE: This may be problematic in a multi-threaded application.



You could use a context manager to temporarily block the polymorphism:



from contextlib import contextmanager
from sqlalchemy import inspect

@contextmanager
def no_poly(class_):
mapper = inspect(class_).mapper
polycol = mapper.polymorphic_on
mapper.polymorphic_on = None
yield class_
mapper.polymorphic_on = polycol

Base.metadata.drop_all(engine)
Base.metadata.create_all(engine)
task = Task(title='Task Title', another_extra='something')
s = Session()
s.add(task)
s.commit()

# opening a new session as if the pk already exists in the
# identity map it will return whatever type that pk is
# pointing at.
s = Session()
with no_poly(Item) as class_:
inst = s.query(class_).all()
print(inst) # [<__main__.Item object at 0x000001443685DDD8>]
s = Session() # new session again.
inst = s.query(Item).all()
print(inst) # [<__main__.Task object at 0x00000144368770B8>]


Something to be mindful of and as noted in the comments in my example, if the identity of the object is already referenced in the Identity Map, then you will get back whatever type is held in there, regardless of the class that you query on.






share|improve this answer















NOTE: This may be problematic in a multi-threaded application.



You could use a context manager to temporarily block the polymorphism:



from contextlib import contextmanager
from sqlalchemy import inspect

@contextmanager
def no_poly(class_):
mapper = inspect(class_).mapper
polycol = mapper.polymorphic_on
mapper.polymorphic_on = None
yield class_
mapper.polymorphic_on = polycol

Base.metadata.drop_all(engine)
Base.metadata.create_all(engine)
task = Task(title='Task Title', another_extra='something')
s = Session()
s.add(task)
s.commit()

# opening a new session as if the pk already exists in the
# identity map it will return whatever type that pk is
# pointing at.
s = Session()
with no_poly(Item) as class_:
inst = s.query(class_).all()
print(inst) # [<__main__.Item object at 0x000001443685DDD8>]
s = Session() # new session again.
inst = s.query(Item).all()
print(inst) # [<__main__.Task object at 0x00000144368770B8>]


Something to be mindful of and as noted in the comments in my example, if the identity of the object is already referenced in the Identity Map, then you will get back whatever type is held in there, regardless of the class that you query on.







share|improve this answer














share|improve this answer



share|improve this answer








edited Nov 26 '18 at 6:30

























answered Nov 25 '18 at 2:38









SuperShootSuperShoot

2,3231024




2,3231024








  • 3





    This seems like it might pose some risks in multithreaded programs, since it modifies the mapper in place.

    – Ilja Everilä
    Nov 26 '18 at 5:48











  • IIja is correct, I don't really want to modify mapper, I was just looking for a query or __mapper_args__ to work somehow.

    – Mehrdad Pedramfar
    Nov 26 '18 at 6:01











  • @IljaEverilä do you have any idea about how to achive this?

    – Mehrdad Pedramfar
    Nov 26 '18 at 6:02











  • Yeh, it's not threadsafe. I'll note that in the answer. Is that a prerequisite in this case?

    – SuperShoot
    Nov 26 '18 at 6:29














  • 3





    This seems like it might pose some risks in multithreaded programs, since it modifies the mapper in place.

    – Ilja Everilä
    Nov 26 '18 at 5:48











  • IIja is correct, I don't really want to modify mapper, I was just looking for a query or __mapper_args__ to work somehow.

    – Mehrdad Pedramfar
    Nov 26 '18 at 6:01











  • @IljaEverilä do you have any idea about how to achive this?

    – Mehrdad Pedramfar
    Nov 26 '18 at 6:02











  • Yeh, it's not threadsafe. I'll note that in the answer. Is that a prerequisite in this case?

    – SuperShoot
    Nov 26 '18 at 6:29








3




3





This seems like it might pose some risks in multithreaded programs, since it modifies the mapper in place.

– Ilja Everilä
Nov 26 '18 at 5:48





This seems like it might pose some risks in multithreaded programs, since it modifies the mapper in place.

– Ilja Everilä
Nov 26 '18 at 5:48













IIja is correct, I don't really want to modify mapper, I was just looking for a query or __mapper_args__ to work somehow.

– Mehrdad Pedramfar
Nov 26 '18 at 6:01





IIja is correct, I don't really want to modify mapper, I was just looking for a query or __mapper_args__ to work somehow.

– Mehrdad Pedramfar
Nov 26 '18 at 6:01













@IljaEverilä do you have any idea about how to achive this?

– Mehrdad Pedramfar
Nov 26 '18 at 6:02





@IljaEverilä do you have any idea about how to achive this?

– Mehrdad Pedramfar
Nov 26 '18 at 6:02













Yeh, it's not threadsafe. I'll note that in the answer. Is that a prerequisite in this case?

– SuperShoot
Nov 26 '18 at 6:29





Yeh, it's not threadsafe. I'll note that in the answer. Is that a prerequisite in this case?

– SuperShoot
Nov 26 '18 at 6:29




















draft saved

draft discarded




















































Thanks for contributing an answer to Stack Overflow!


  • Please be sure to answer the question. Provide details and share your research!

But avoid



  • Asking for help, clarification, or responding to other answers.

  • Making statements based on opinion; back them up with references or personal experience.


To learn more, see our tips on writing great answers.




draft saved


draft discarded














StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53458005%2fget-sqlalchemy-base-class-object-instead-of-children%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown





















































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown

































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown







這個網誌中的熱門文章

Xamarin.form Move up view when keyboard appear

Post-Redirect-Get with Spring WebFlux and Thymeleaf

Anylogic : not able to use stopDelay()