fastapi 操作数据库

1. Installation

from sqlalchemy import create_engine
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker

SQLALCHEMY_DATABASE_URL = "sqlite:///./test.db"

engine = create_engine(
    SQLALCHEMY_DATABASE_URL, connect_args={"check_same_thread": False}
)
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)

Base = declarative_base()

3.2 models.py

第二步需要定义我们的表结构，这里定义了User表存储用户数据，item表用于存储物品数据，两者关系是一对多。

from typing import List

from pydantic import BaseModel


class ItemBase(BaseModel):
    title: str
    description: str = None


class ItemCreate(ItemBase):
    pass


class ItemUpdate(ItemBase):
    pass


class Item(ItemBase):
    id: int
    owner_id: int

    class Config:
        orm_mode = True


class UserBase(BaseModel):
    email: str


class UserCreate(UserBase):
    password: str


class UserUpdate(UserBase):
    is_active: bool


class User(UserBase):
    id: int
    is_active: bool
    items: List[Item] = []

    class Config:
        orm_mode = True

3.4 crud.py

接下来就是实际完成CRUD，官网上没有对update、delete做实例展示，这里补充一下。

from typing import List

from fastapi import Depends, FastAPI, HTTPException
from sqlalchemy.orm import Session

from . import crud, models, schemas
from .database import SessionLocal, engine

models.Base.metadata.create_all(bind=engine)

app = FastAPI()


# Dependency
def get_db():
    try:
        db = SessionLocal()
        yield db
    finally:
        db.close()


@app.post("/users/", response_model=schemas.User)
def create_user(user: schemas.UserCreate, db: Session = Depends(get_db)):
    db_user = crud.get_user_by_email(db, email=user.email)
    if db_user:
        raise HTTPException(status_code=400, detail="Email already registered")
    return crud.create_user(db=db, user=user)


@app.get("/users/", response_model=List[schemas.User])
def read_users(skip: int = 0, limit: int = 100, db: Session = Depends(get_db)):
    users = crud.get_users(db, skip=skip, limit=limit)
    return users


@app.get("/users/{user_id}", response_model=schemas.User)
def read_user(user_id: int, db: Session = Depends(get_db)):
    db_user = crud.get_user(db, user_id=user_id)
    if db_user is None:
        raise HTTPException(status_code=404, detail="User not found")
    return db_user


@app.delete('/users/{user_id}', response_model=schemas.User)
def delete_user(user_id: int, db: Session = Depends(get_db)):
    db_user = crud.delete_user(db, user_id=user_id)
    if db_user is None:
        raise HTTPException(status_code=404, detail="User not found")
    return db_user


@app.put("/users/{user_id}", response_model=schemas.User)
def update_user(user_id: int, update_user: schemas.UserUpdate, db: Session = Depends(get_db)):
    updated_user = crud.update_user(db, user_id, update_user)
    if updated_user is None:
        raise HTTPException(status_code=404, detail="User not found")
    return updated_user


@app.post("/users/{user_id}/items/", response_model=schemas.Item)
def create_item_for_user(
    user_id: int, item: schemas.ItemCreate, db: Session = Depends(get_db)
):
    return crud.create_user_item(db=db, item=item, user_id=user_id)


@app.get("/items/", response_model=List[schemas.Item])
def read_items(skip: int = 0, limit: int = 100, db: Session = Depends(get_db)):
    items = crud.get_items(db, skip=skip, limit=limit)
    return items


@app.put("/items/{user_id}/{item_id}/", response_model=schemas.User)
def relate_user_item(user_id: int, item_id: int, db: Session = Depends(get_db)):
    user = crud.relate_user_item(db=db, item_id=item_id, user_id=user_id)
    return user


@app.put("/items/{item_id}", response_model=schemas.Item)
def update_item(item_id: int, update_item: schemas.ItemUpdate, db: Session = Depends(get_db)):
    updated_item = crud.update_item(db, item_id, update_item)
    if updated_item is None:
        raise HTTPException(status_code=404, detail="Item not found")
    return updated_item


@app.delete('/items/{item_id}', response_model=schemas.Item)
def delete_item(item_id: int, db: Session = Depends(get_db)):
    db_item = crud.delete_item(db, item_id=item_id)
    if db_item is None:
        raise HTTPException(status_code=404, detail="User not found")
    return db_item

4. Tests

在文件路径下执行，--reload当代码有修改时，可以自动加载。

uvicorn sql_app.main:app --reload

可以通过postman发送请求做测试

最后fastapi还可以自动生成文档，可以访问http://127.0.0.1:8000/docs

详细 https://blog.csdn.net/lilygg/article/details/110851138

fastapi 中文文档： https://www.w3cschool.cn/fastapi/fastapi-lgip3ld3.html