On Sat, Aug 22, 2020, at 12:33 PM, Saakshaat Singh wrote: > Thank you for looking into it Mike. I'll post an example today. > > But looking at your SQLAlchemy execution, I noticed that you're only passing > a value for the `child_value` field while the Parent class is polymorphic on > the `ChildType` enum. So maybe it holds value to also pass values for the > `resource_type` and `general_field` fields?
Most likely but I was not able to make the mappings run, and once I saw what you were doing with the columns I don't see a way to make those mappings work. > On Saturday, August 22, 2020 at 9:19:19 AM UTC-7 Mike Bayer wrote: >> __ >> Hi, I have no idea what the problem is and would need a fully runnable MCVE. >> Below is part of your test which I've tried to get running but it still >> errors out on identifiers missing and such, additionally I need a working >> example of exactly the session operations you are trying to achieve. It >> might be easier to post the working code example as a github question: >> https://github.com/sqlalchemy/sqlalchemy/issues >> >> code so far below: >> >> import enum >> >> import sqlalchemy as sa >> from sqlalchemy.dialects.postgresql import ARRAY >> from sqlalchemy.dialects.postgresql import HSTORE >> from sqlalchemy.ext.mutable import MutableDict >> from sqlalchemy.ext.declarative import declarative_base >> >> class ChildType(enum.Enum): >> sub_1 = "sub_1" >> sub_2 = "sub_2" >> sub_3 = "sub_3" >> >> >> class ParentModel(declarative_base()): >> __table__ = "parent" >> general_field = sa.Column(sa.String) >> resource_type = sa.Column(sa.Enum(ChildType)) >> >> __mapper_args__ = { >> "polymorphic_identity": "parent", >> "polymorphic_on": resource_type, >> } >> >> >> class Sub1(ParentModel): >> @sa.declared_attr >> def child_value(cls): >> return ParentModel.__table__.c.get( >> "child_value", sa.Column(sa.Integer, nullable=True) >> ) >> >> __mapper_args__ = {"polymorphic_identity": ChildType.sub_1} >> >> >> class Sub2(ParentModel): >> @sa.declared_attr >> def child_value(cls): >> return ParentModel.__table__.c.get( >> "child_value", sa.Column(sa.Boolean, nullable=True) >> ) >> >> __mapper_args__ = {"polymorphic_identity": ChildType.sub_2} >> >> >> class Sub3(ParentModel): >> @sa.declared_attr >> def child_value(cls): >> return ParentModel.__table__.c.get( >> "child_value", sa.Column(ARRAY(MutableDict.as_mutable(HSTORE))) >> ) >> >> __mapper_args__ = {"polymorphic_identity": ChildType.sub_3} >> >> >> >> e = create_engine("postgresql://scott:tiger@pg12/test", echo=True) >> ParentModel.drop_all(e) >> ParentModel.create_all(e) >> s = Session(e) >> >> s.add(Sub3(child_value=[{"foo": "bar"}])) >> s.commit() >> >> >> >> >> On Fri, Aug 21, 2020, at 8:06 PM, Saakshaat Singh wrote: >>> Hi, >>> >>> I'm working with SQLAlchemy and Postgres and I have a polymorphic model >>> whose subclasses have a field with the same name. To allow this field to >>> co-exist with the others and not cause any name conflicts, I'm using the >>> `declare_attr` decorator from SQLAlchemy. >>> >>> This solution works well for fields consisting of primary data types, >>> however when I try to use Postgres's HSTORE to store dictionary values, >>> SQLAlchemy complains with: >>> >>> sqlalchemy.exc.ProgrammingError: (psycopg2.ProgrammingError) can't adapt >>> type 'dict' >>> >>> >>> My guess is that this happens because `declared_attr` has constrains on >>> which data types its fields have. >>> >>> Here's an example of how my models look: >>> >>> *import enum * >>> ** >>> *import sqlalchemy as sa* >>> *from sqlalchemy.dialects.postgres import ARRAY, HSTORE* >>> *from sqlalchemy.ext.mutables import MutableDict* >>> ** >>> *class ChildType(enum.Enum):* >>> * sub_1 = "sub_1"* >>> * sub_2 = "sub_2"* >>> * sub_3 = "sub_3"* >>> ** >>> *class ParentModel(sa.declarative_base()):* >>> * __table__ = 'parent'* >>> * general_field = sa.Column(sa.String)* >>> * r_type = sa.Column(sa.Enum(ChildType))* >>> * * >>> * __mapper_args__ = {* >>> * 'polymorphic_identity': 'parent',* >>> * 'polymorphic_on': resource_type* >>> * }* >>> * * >>> * * >>> *class Sub1(ParentModel):* >>> * @sa.declared_attr* >>> * def child_value(cls):* >>> * return ParentModel.__table__.c.get('child_value', >>> sa.Column(sa.Integer, nullable=True))* >>> * * >>> * __mapper_args__ = {* >>> * 'polymorphic_identity': ChildType.sub_1* >>> * }* >>> * * >>> *class Sub2(ParentModel):* >>> * @sa.declared_attr* >>> * def child_value(cls):* >>> * return ParentModel.__table__.c.get('child_value', >>> sa.Column(sa.Boolean, nullable=True))* >>> * * >>> * __mapper_args__ = {* >>> * 'polymorphic_identity': ChildType.sub_2* >>> * }* >>> * * >>> *class Sub3(ParentModel):* >>> * @sa.declared_attr* >>> * def child_value(cls):* >>> * return ParentModel.__table__.c.get('child_value', >>> sa.Column(ARRAY(MutableDict.as_mutable(HSTORE))))* >>> * * >>> * __mapper_args__ = {* >>> * 'polymorphic_identity': ChildType.sub_3* >>> * }* >>> >>> >>> Can anyone help me out with a potential workaround/solution? >>> >>> Thanks! >>> >>> -- >>> 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 view this discussion on the web visit >>> https://groups.google.com/d/msgid/sqlalchemy/0421937b-08f0-470d-8067-43430bfc1ca8n%40googlegroups.com >>> >>> <https://groups.google.com/d/msgid/sqlalchemy/0421937b-08f0-470d-8067-43430bfc1ca8n%40googlegroups.com?utm_medium=email&utm_source=footer>. >> > > -- > 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 view this discussion on the web visit > https://groups.google.com/d/msgid/sqlalchemy/c37ddcfb-ad33-45d0-9288-4d46d6927538n%40googlegroups.com > > <https://groups.google.com/d/msgid/sqlalchemy/c37ddcfb-ad33-45d0-9288-4d46d6927538n%40googlegroups.com?utm_medium=email&utm_source=footer>. -- 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. 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