Thank you very much! It is working now. My mistake was to use @declared_attr to create a unique sequence per mapper, and that was not working of course.
среда, 25 апреля 2018 г., 22:04:58 UTC+3 пользователь Stanislav Lobanov написал: > > Hello! > > I have a base model class with "id" field, which is primary key and also > not nullable. It does not have autoincrement feature, but uses custom > sequence manually to assign it's value. > > There are standard on table / sequence naming: > > class Base: > id = Column(Integer, primary_key=True, nullable=False) > > > class A(Base): > __tablename__ = 'a' > > > class B(Base): > __tablename__ = 'b' > > > > What i need is to do two things: > > 1. Automatically add sequences to A and B tables (in ORM context, > mappers), named "__tablename__$seq" -> 'a$seq' and 'b$seq'. By sequences i > mean an attribute of type Sequence. > 2. Somehow associate it with "id" column, so the sequence can be > automatically created after "create_all()" function call. > > I tried to use this approach: Associating a Sequence as the Server Side > Default ( > http://docs.sqlalchemy.org/en/latest/core/defaults.html#associating-a-sequence-as-the-server-side-default > ) > but did not succeed because sequence name is always hardcoded in base > class, but in my case it must be autogenerated based on custom naming rule. > > I have spent four hours trying different techniques but did not succeed > with this. > > 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 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.
