Re: [sqlalchemy] Re: Trying to find a way to sort a query given the name of one of its columns
On Mon, Jun 12, 2023, at 3:12 AM, Lele Gaifax wrote: > Lele Gaifax writes: > >> I will study the contains_eager() alternative and try to modernize my >> code that still uses that idiom. > > After reading the different sections (narrative and reference), I wonder > if there is a case where the joinedload() has some advantage over > contains_eager(), or if the former, being "the oldest style of eager > loading in SA ORM" is kept mainly for backward compatibility. joinedload() is a lot easier to use for sure and yes there are probably some very nested/ crazyish cases where joinedload "works" and contains_eager either doesnt quite work or is very difficult to make it work. > > bye, lele. > -- > nickname: Lele Gaifax | Quando vivrò di quello che ho pensato ieri > real: Emanuele Gaifas | comincerò ad aver paura di chi mi copia. > l...@metapensiero.it | -- Fortunato Depero, 1929. > > -- > 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/87r0qh9mrs.fsf%40metapensiero.it. -- 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/cc58ebb7-6489-4e05-8d21-18bd68b91933%40app.fastmail.com.
[sqlalchemy] Re: Trying to find a way to sort a query given the name of one of its columns
Lele Gaifax writes: > I will study the contains_eager() alternative and try to modernize my > code that still uses that idiom. After reading the different sections (narrative and reference), I wonder if there is a case where the joinedload() has some advantage over contains_eager(), or if the former, being "the oldest style of eager loading in SA ORM" is kept mainly for backward compatibility. bye, lele. -- nickname: Lele Gaifax | Quando vivrò di quello che ho pensato ieri real: Emanuele Gaifas | comincerò ad aver paura di chi mi copia. l...@metapensiero.it | -- Fortunato Depero, 1929. -- 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/87r0qh9mrs.fsf%40metapensiero.it.
[sqlalchemy] Re: Trying to find a way to sort a query given the name of one of its columns
Federico Caselli writes:
> Also you may not need the col_by_name at all for order_by, since you can
> pass the string in order_by directly:
> https://docs.sqlalchemy.org/en/20/tutorial/data_select.html#tutorial-order-by-label
> This case is still not supported, since doing "query.order_by('firstname')"
> raises "column not found".
Yes, but in rare cases I exploited its ability of findind a column not
"exposed" in the select, belonging to one of the joined tables, for
example to have a stable sort.
> (ps: github discussions should be preferred to share code snippets)
Sorry, note taken.
ciao, lele.
--
nickname: Lele Gaifax | Quando vivrò di quello che ho pensato ieri
real: Emanuele Gaifas | comincerò ad aver paura di chi mi copia.
l...@metapensiero.it | -- Fortunato Depero, 1929.
--
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/87v8ft9ny3.fsf%40metapensiero.it.
[sqlalchemy] Re: Trying to find a way to sort a query given the name of one of its columns
Also you may not need the col_by_name at all for order_by, since you can
pass the string in order_by directly:
https://docs.sqlalchemy.org/en/20/tutorial/data_select.html#tutorial-order-by-label
This case is still not supported, since doing "query.order_by('firstname')"
raises "column not found".
(ps: github discussions should be preferred to share code snippets)
On Saturday, 10 June 2023 at 21:05:35 UTC+2 Lele Gaifax wrote:
> "Mike Bayer" writes:
>
> > it looks like you're trying to add an ORDER BY to the table that's
> > only there via joinedload(). That's *really* not something we
> > anticipate and it would be better if people proposed perhaps ad-hoc
> > order_by expressions to be added to common loader options like
> > joinedload() and selectinload(), in the same way that we offer ad-hoc
> > WHERE criteria for these options now. as you are probably aware, the
> > current way to do "joinedload with custom criteria / ordering / etc"
> > is to write the query using outerjoin() and order_by() normally, then
> > use contains_eager().
>
> Oh, thanks a lot for this!. Accordingly with the git history, I
> introduced that test to address a deprecation warning issued by SA 1.4+
> load_only()...
>
> I will study the contains_eager() alternative and try to modernize my
> code that still uses that idiom.
>
> bye, lele.
> --
> nickname: Lele Gaifax | Quando vivrò di quello che ho pensato ieri
> real: Emanuele Gaifas | comincerò ad aver paura di chi mi copia.
> le...@metapensiero.it | -- Fortunato Depero, 1929.
>
>
--
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/07785e0a-27e3-4977-857a-34cda38903f8n%40googlegroups.com.
[sqlalchemy] Re: Trying to find a way to sort a query given the name of one of its columns
"Mike Bayer" writes: > it looks like you're trying to add an ORDER BY to the table that's > only there via joinedload(). That's *really* not something we > anticipate and it would be better if people proposed perhaps ad-hoc > order_by expressions to be added to common loader options like > joinedload() and selectinload(), in the same way that we offer ad-hoc > WHERE criteria for these options now. as you are probably aware, the > current way to do "joinedload with custom criteria / ordering / etc" > is to write the query using outerjoin() and order_by() normally, then > use contains_eager(). Oh, thanks a lot for this!. Accordingly with the git history, I introduced that test to address a deprecation warning issued by SA 1.4+ load_only()... I will study the contains_eager() alternative and try to modernize my code that still uses that idiom. bye, lele. -- nickname: Lele Gaifax | Quando vivrò di quello che ho pensato ieri real: Emanuele Gaifas | comincerò ad aver paura di chi mi copia. l...@metapensiero.it | -- Fortunato Depero, 1929. -- 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/87zg576sun.fsf%40metapensiero.it.
