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+unsubscr...@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/51688c7d-cca2-433a-8690-f0996ce5f8a7%40www.fastmail.com.