On Fri, Jun 29, 2018 at 4:20 PM, Marcus Mann <[email protected]> wrote: > And why do you use the doc property in > data = column_property(A.data, doc="B's data") > and why do you change A.data in class B?
well you said you wanted a "description", which I am still unclear what you mean by that, "doc" is used to assign a docstring to a column attribute. It places it in __doc__ and shows up in Sphinx doumentation, for example. Then you said you wanted to override it on B so I re-wrapped it. I'm not sure that's what you want now, your example looks more like you want the value of the attribute to be fixed on the subclass, but persisted on the superclass? i don't see how that would work yet. > > On Fri, Jun 29, 2018 at 4:18 PM, Mike Bayer <[email protected]> > wrote: >> >> a Column is a Core schema construct that is not part of the ORM. The >> ORM maps a Column to your mapped class using a column_property() that >> wraps around it. When you use declarative_base, the declarative >> system is automatically generating these column_property() objects for >> each Column you have by itself. >> >> On Fri, Jun 29, 2018 at 4:16 PM, Marcus Mann <[email protected]> wrote: >> > I guess I am still a little confused about the relationship between >> > Column >> > and column_property >> > >> > On Fri, Jun 29, 2018 at 4:14 PM, Mike Bayer <[email protected]> >> > wrote: >> >> >> >> On Fri, Jun 29, 2018 at 11:46 AM, Marcus Mann <[email protected]> >> >> wrote: >> >> > When I said description, I just meant a simple string that describes >> >> > the >> >> > object, not a python docstring. Just an example column. >> >> >> >> so....does my example answer your question? >> >> >> >> >> >> >> >> >> >> > >> >> > On Friday, June 29, 2018 at 9:49:07 AM UTC-4, Mike Bayer wrote: >> >> >> >> >> >> your question is getting no answers because it is vague and doesn't >> >> >> provide any code. what's a "description"? you mean a Python >> >> >> docstring ? Python attributes don't have a __doc__ normally, if >> >> >> you >> >> >> mean the "doc" parameter, just make a separate property: >> >> >> >> >> >> class A(Base): >> >> >> __tablename__ = 'a' >> >> >> >> >> >> id = Column(Integer, primary_key=True) >> >> >> >> >> >> data = column_property(Column(String), doc="the data") >> >> >> >> >> >> >> >> >> class B(A): >> >> >> __tablename__ = 'b' >> >> >> >> >> >> id = Column(ForeignKey('a.id'), primary_key=True) >> >> >> >> >> >> data = column_property(A.data, doc="B's data") >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> On Fri, Jun 29, 2018 at 8:41 AM, Marcus Mann <[email protected]> >> >> >> wrote: >> >> >> > >> >> >> > >> >> >> > >> >> >> > https://stackoverflow.com/questions/51046900/how-to-access-override-defaults-on-parents-attribute-in-sql-alchemy >> >> >> > >> >> >> > -- >> >> >> > 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 [email protected]. >> >> >> > To post to this group, send email to [email protected]. >> >> >> > 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 [email protected]. >> >> > To post to this group, send email to [email protected]. >> >> > 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 [email protected]. >> >> To post to this group, send email to [email protected]. >> >> 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 [email protected]. >> > To post to this group, send email to [email protected]. >> > 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 [email protected]. >> To post to this group, send email to [email protected]. >> 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 [email protected]. > To post to this group, send email to [email protected]. > 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 [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/d/optout.
