如何映射列来创建自增主键？

Question

我的 SQLAlchemy 2.0 与 SQLite 数据库的映射列正在创建一个主键列，因此我无法插入。

模式类别：

import datetime
from typing import Optional

from sqlalchemy import String, TIMESTAMP, Integer
from sqlalchemy import func
from sqlalchemy.dialects import postgresql, sqlite
from sqlalchemy.orm import DeclarativeBase
from sqlalchemy.orm import Mapped, mapped_column
from sqlalchemy.schema import CreateTable
from typing_extensions import Annotated

timestamp = Annotated[datetime.datetime, mapped_column(nullable=False, server_default=func.CURRENT_TIMESTAMP()),]


class Base(DeclarativeBase):
    type_annotation_map = {datetime.datetime: TIMESTAMP(timezone=True), }


class UserClass(Base):
    __tablename__ = "user"

    id: Mapped[Integer] = mapped_column(Integer, primary_key=True, autoincrement=True)
    name: Mapped[str] = mapped_column(String(50))
    fullname: Mapped[Optional[str]] = mapped_column(String(50), nullable=False)
    nickname: Mapped[Optional[str]] = mapped_column(String(30))
    date: Mapped[datetime.datetime]
    status: Mapped[str]
    created_at: Mapped[timestamp] = mapped_column(server_default=func.UTC_TIMESTAMP())
    updated_at: Mapped[timestamp] = mapped_column(server_default=func.UTC_TIMESTAMP())

表：

CREATE TABLE user (
    id BIGINT NOT NULL,
    name VARCHAR(50) NOT NULL,
    fullname VARCHAR(50) NOT NULL,
    nickname VARCHAR(30),
    date TIMESTAMP NOT NULL,
    status VARCHAR NOT NULL,
    created_at TIMESTAMP DEFAULT (UTC_TIMESTAMP()) NOT NULL,
    updated_at TIMESTAMP DEFAULT (UTC_TIMESTAMP()) NOT NULL,
    PRIMARY KEY (id)
);

插入命令：

INSERT INTO user (name, fullname, nickname, date, status, created_at, updated_at) VALUES ('John', 'John Doe', 'Johnny', '2024-09-21 19:09:51.484769', 'active', '2024-09-21 19:09:51.490379', '2024-09-21 19:09:51.490400')

当我插入时，它给出以下错误消息：

sqlite3.IntegrityError）NOT NULL 约束失败：user.id

我认为在 SQLite 中需要像这样创建主键：

id integer primary key autoincrement

。如何映射列来创建这样的主键？

Answer 1

您还需要创建一个负责自动递增的序列：

class UserClass(Base):
    __tablename__ = "user"

    id_seq = sa.Sequence("seq_user_id", metadata= Base.metadata)

    id: Mapped[Integer] = mapped_column(Integer, primary_key=True, server_default=id_seq.next_value())
    name: Mapped[str] = mapped_column(String(50))
    fullname: Mapped[Optional[str]] = mapped_column(String(50), nullable=False)
    nickname: Mapped[Optional[str]] = mapped_column(String(30))
    date: Mapped[datetime.datetime]
    status: Mapped[str]
    created_at: Mapped[timestamp] = mapped_column(server_default=func.UTC_TIMESTAMP())
    updated_at: Mapped[timestamp] = mapped_column(server_default=func.UTC_TIMESTAMP())