SQLAlchemy 2.0 教程

创建引擎

from sqlalchemy import create_engine
engine = create_engine("sqlite://", echo=True)

echo=True 表示将输出log

声明模型

from typing import List
from typing import Optional
from sqlalchemy import ForeignKey
from sqlalchemy import String
from sqlalchemy.orm import DeclarativeBase
from sqlalchemy.orm import Mapped
from sqlalchemy.orm import mapped_column
from sqlalchemy.orm import relationship

class Base(DeclarativeBase):
    pass

class User(Base):
    __tablename__ = "user_account"
    id: Mapped[int] = mapped_column(primary_key=True)
    name: Mapped[str] = mapped_column(String(30))
    fullname: Mapped[Optional[str]]
    addresses: Mapped[List["Address"]] = relationship(
        back_populates="user", cascade="all, delete-orphan"
    )
    def __repr__(self) -> str:
        return f"User(id={self.id!r}, name={self.name!r}, fullname={self.fullname!r})"

class Address(Base):
    __tablename__ = "address"
    id: Mapped[int] = mapped_column(primary_key=True)
    email_address: Mapped[str]
    user_id: Mapped[int] = mapped_column(ForeignKey("user_account.id"))
    user: Mapped["User"] = relationship(back_populates="addresses")
    def __repr__(self) -> str:
        return f"Address(id={self.id!r}, email_address={self.email_address!r})"