This works! Could you explain a little about this differences by using
select_from here? I think this is very important and useful, really want to
learn it right.
On Wednesday, November 10, 2021 at 5:55:44 AM UTC-8 Mike Bayer wrote:
> try calling:
>
> query(C.symbol_from_a).select_from(C)
>
>
>
> On Wed, Nov 10, 2021, at 4:50 AM, niuji...@gmail.com wrote:
>
> class A(Base):
> primary_id = Column(Integer, prirmary_key=True)
> some_A_marker = Column(String)
>
> class B(Base):
> primary_id = Column(Integer, primary_key=True)
> referencing_A_id = Column(Integer, ForeignKey(A.primary_id))
>
> class C(Base):
> primary_id = Column(Integer, primary_key=True)
> basedOn_B_id = Column(Integer, ForeignKey(B.primary_id))
> symbol_from_A = column_property(
>
> sasql.select(A.some_A_marker).select_from(A).join(B).where(B.primary_id ==
> C.basedOn_B_id).correlate(C).scalar_subquery().label("symbol_from_A")
> )
>
>
> When I query this highlighted column_property along with the whole object,
> it works fine:
>
> >>> sess.query(C, C.symbol_from_A).all()
>
> However, when I query this column_property alone, it doesn't work:
>
> >>>sess.query(C.symbol_from_A).distinct().all()
>
> I noticed that somehow the correlated subquery wasn't executed property
> when query that column_property independently.
>
> How to solve this?
>
>
> --
> 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
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>
>
--
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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