Postgresql 我可以使用 SQLAlchemy 映射数据类创建 Postgres `GENERATED ALWAYS AS` 列吗

你差一点就成功了，你可以用这个.

from sqlalchemy import Computed, create_engine, func, select
from sqlalchemy.orm import Mapped, MappedAsDataclass, DeclarativeBase, Session, mapped_column

class Base(MappedAsDataclass, DeclarativeBase):
    pass

class Collection(Base):
    __tablename__ = 'collections'
    collection_id: Mapped[int] = mapped_column(init=False, primary_key=True)
    collection_name: Mapped[str] = mapped_column(default=None, unique=True)
    collection_ezname: Mapped[str] = mapped_column(Computed(func.REGEXP_REPLACE(collection_name, ' ', '_')), unique=True, init=False)

engine = create_engine("")

Base.metadata.drop_all(engine)
Base.metadata.create_all(engine)

with Session(engine) as session:
    session.add(Collection('something with space'))
    session.commit()

with Session(engine) as session:
    for i in session.scalars(select(Collection)):
        print(i)

这将生成以下内容

CREATE TABLE collections (
        collection_id SERIAL NOT NULL, 
        collection_name VARCHAR NOT NULL, 
        collection_ezname VARCHAR GENERATED ALWAYS AS (REGEXP_REPLACE(collection_name, ' ', '_')) STORED NOT NULL, 
        PRIMARY KEY (collection_id), 
        UNIQUE (collection_name), 
        UNIQUE (collection_ezname)
)

输出

Collection(collection_id=1, collection_name='something with space', collection_ezname='something_with space')个

You may have to change your regex as it currently does not replace multiple spaces and other scenarios I can't think of. Probably 100?