On Tue, Apr 03, 2018 at 10:05:22AM -0400, Mike Bayer wrote: > On Tue, Apr 3, 2018 at 9:59 AM, Julien Cigar <julien.ci...@gmail.com> wrote: > > On Tue, Apr 03, 2018 at 12:20:53PM +0200, Julien Cigar wrote: > >> On Thu, Mar 22, 2018 at 10:58:56AM +0100, Julien Cigar wrote: > >> > On Tue, Mar 20, 2018 at 08:32:14PM -0400, Mike Bayer wrote: > >> > > I think it would be a lot easier to have the corresponding translation > >> > > linked off using relationship(). can you work with that? > >> > > >> > >> Hello Mike, > >> > >> I tried with relationships, but I'm not too satisfied with the generated > >> SQL, which makes me belived that I'm doing something wrong.. > >> > >> I've GIST the relevant parts of my mappers and the generated SQL at > >> https://gist.github.com/silenius/0fedf2bcb92b7e5c6f27732678c5baa0 > >> > >> I'm wondering if overriding the 'translations' relationship as I do is > >> the correct approach ..? In theory the "ContentTranslation" should be > >> somewhat "dynamic", but I wonder if SQLAlchemy supports something like > >> this .. ? By "dynamic" I mean it should be DocumentTranslation, or > >> EventTranslation, ... regarding of the polymorphic_identity of the "other > >> side" of the relationship > >> > >> Thanks ! > >> > >> Julien > > > > OK, I think I found the "correct way" to do it, thanks to the new > > polymorphic_load parameter of SQLAlchemy 1.2: > > https://gist.github.com/silenius/5afc06e670f5f7dda548dc5a0d0583df > > > > (I've also added a trigger on the content_translation table so > > "duplicate" the content_type_id column (as setting polymorphic_on on > > an SQL statement isn't supported)) > > > > With polymorphic_load='inline' and lazy='subquery' I have only two SQL > > statements to load the whole entities + associated translations (while > > being "strict" on the SQL relationships) > > > > any comments ? :) > > > > > wow, I already don't even remember what polymorphic_load does. I > need to work your example into a declarative demo so I can play with > it. but I am encouraged.
(... and, although I use SQLAlchemy since many years, I'm always impressed how flexible and well written it is) I'm currently at $work but I can write a small declarative demo as soon as I got home > > > > > Thanks, > > Julien > > > >> > >> > I could .. :) I'll make some "helper functions" or maybe a custom Query > >> > object, with maybe some proxy-like properties too > >> > > >> > Thanks > >> > > >> > > > >> > > On Tue, Mar 20, 2018 at 9:19 AM, Julien Cigar <julien.ci...@gmail.com> > >> > > wrote: > >> > > > Hello, > >> > > > > >> > > > I have an existing CMS-like application which uses joined table > >> > > > inheritance at its core. Basically I have a base class Content from > >> > > > which all other classes (Folder, Document, Event, File, ...) > >> > > > inherit.=20 > >> > > > It works wonderfully well. This is my (Postgre)SQL schema if you > >> > > > are=20 > >> > > > interested:=20 > >> > > > https://gist.githubusercontent.com/silenius/2e0f69fadfde9877e32c5b778efd39a= > >> > > > f/raw/f08e2af2f7cd239c865777d1e54342ee53608520/sa.sql > >> > > > > >> > > > Now we'd like to support multiple languages. We plan to add an=20 > >> > > > additional table for each inherited class (additional translation=20 > >> > > > table approach), so basically we'll have something like: > >> > > > > >> > > > content_type > >> > > > | > >> > > > | > >> > > > content --- content_translation > >> > > > | > >> > > > | > >> > > > document --- document_translation > >> > > > > >> > > > Currently I have a polymorphic_on=3Dtables.content.c.content_type_id > >> > > > on=20 > >> > > > the base mapper (Content) and > >> > > > polymorphic_identity=3Dget_type_id(config, > >> > > > 'some_content_type_name') for each inherited mapper (the get_type_id > >> > > > function simply return the content_type ID: > >> > > > https://gist.github.com/silenius/25b8f46192b5b9b23477fe0c541bd9f3 ) > >> > > > > >> > > > As the application is quite large I'd like to avoid having to > >> > > > refactor a > >> > > > lot of code. > >> > > > > >> > > > I wondered what would be the best SQLAlchemy approach to do this? > >> > > > > >> > > > For example let's say I have something like this in my application: > >> > > > session.query(Document).all() which SQLAlchemy translates as: > >> > > > > >> > > > SELECT .. FROM content=20 > >> > > > JOIN document ON content.id =3D document.content_id > >> > > > > >> > > > Is there some mapper configuration that I could change so that it > >> > > > translates now as: > >> > > > > >> > > > SELECT .. FROM content=20 > >> > > > JOIN content_translation=20 > >> > > > ON content.id =3D content_translation.content_id=20 > >> > > > AND content_translation.lang =3D 'some_language_code'=20 > >> > > > JOIN document ON document.content_id =3D content.id=20 > >> > > > JOIN document_translation=20 > >> > > > ON document_translation.document_id =3D document.content_id=20 > >> > > > AND document_translation.lang =3D 'some_language_code' > >> > > > > >> > > > If not, what would be the best approach? > >> > > > > >> > > > Thanks ! > >> > > > > >> > > > > >> > > > -- > >> > > > Julien Cigar > >> > > > Belgian Biodiversity Platform (http://www.biodiversity.be) > >> > > > PGP fingerprint: EEF9 F697 4B68 D275 7B11 6A25 B2BB 3710 A204 23C0 > >> > > > No trees were killed in the creation of this message. > >> > > > However, many electrons were terribly inconvenienced. > >> > > > > >> > > > -- > >> > > > 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 post to this group, send email to sqlalchemy@googlegroups.com. > >> > > > Visit this group at https://groups.google.com/group/sqlalchemy. > >> > > > For more options, visit https://groups.google.com/d/optout. > >> > > > >> > > -- > >> > > 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 post to this group, send email to sqlalchemy@googlegroups.com. > >> > > Visit this group at https://groups.google.com/group/sqlalchemy. > >> > > For more options, visit https://groups.google.com/d/optout. > >> > > >> > -- > >> > Julien Cigar > >> > Belgian Biodiversity Platform (http://www.biodiversity.be) > >> > PGP fingerprint: EEF9 F697 4B68 D275 7B11 6A25 B2BB 3710 A204 23C0 > >> > No trees were killed in the creation of this message. > >> > However, many electrons were terribly inconvenienced. > >> > > >> > -- > >> > 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 post to this group, send email to sqlalchemy@googlegroups.com. > >> > Visit this group at https://groups.google.com/group/sqlalchemy. > >> > For more options, visit https://groups.google.com/d/optout. > >> > >> > >> > >> -- > >> Julien Cigar > >> Belgian Biodiversity Platform (http://www.biodiversity.be) > >> PGP fingerprint: EEF9 F697 4B68 D275 7B11 6A25 B2BB 3710 A204 23C0 > >> No trees were killed in the creation of this message. > >> However, many electrons were terribly inconvenienced. > >> > >> -- > >> 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 post to this group, send email to sqlalchemy@googlegroups.com. > >> Visit this group at https://groups.google.com/group/sqlalchemy. > >> For more options, visit https://groups.google.com/d/optout. > > > > > > > > -- > > Julien Cigar > > Belgian Biodiversity Platform (http://www.biodiversity.be) > > PGP fingerprint: EEF9 F697 4B68 D275 7B11 6A25 B2BB 3710 A204 23C0 > > No trees were killed in the creation of this message. > > However, many electrons were terribly inconvenienced. > > > > -- > > 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 post to this group, send email to sqlalchemy@googlegroups.com. > > Visit this group at https://groups.google.com/group/sqlalchemy. > > For more options, visit https://groups.google.com/d/optout. > > -- > 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 post to this group, send email to sqlalchemy@googlegroups.com. > Visit this group at https://groups.google.com/group/sqlalchemy. > For more options, visit https://groups.google.com/d/optout. -- Julien Cigar Belgian Biodiversity Platform (http://www.biodiversity.be) PGP fingerprint: EEF9 F697 4B68 D275 7B11 6A25 B2BB 3710 A204 23C0 No trees were killed in the creation of this message. However, many electrons were terribly inconvenienced. -- 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 post to this group, send email to sqlalchemy@googlegroups.com. Visit this group at https://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/d/optout.
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