FastAPI使用异步motor实现对mongodb的增删改查

一、环境准备：

需要有mongodb和poetry以及Python3.10+

二、克隆示例代码到本地

git clone git@github.com:waketzheng/fastapi_async_mongo_demo.git

三、安装依赖

cd fastapi_async_mongo_demo
poetry shell
poetry install

四、启动服务

python app/main.py

五、访问本地文档

http://localhost:8000/docs

六、代码详解：

目录如下：

.
├── app
│   ├── db.py
│   ├── main.py
│   ├── schemas
│   │   ├── __init__.py
│   │   ├── item.py
│   │   └── user.py
│   ├── utils.py
│   └── views.py
├── poetry.lock
├── pyproject.toml
└── README.md

1. 数据库连接（app/db.py）

from pathlib import Path
from typing import TYPE_CHECKING
 
import motor.motor_asyncio
 
if TYPE_CHECKING:
    from motor.core import AgnosticClient
 
client: "AgnosticClient" = motor.motor_asyncio.AsyncIOMotorClient("localhost", 27017)
db_name = Path(__file__).parent.parent.name.replace("-", "_")
database = client[db_name]
github/fastapi_async_mongo_demo [main●] » vi app/db.py
github/fastapi_async_mongo_demo [main●] » cat app/db.py
from pathlib import Path
from typing import TYPE_CHECKING
 
import motor.motor_asyncio
 
if TYPE_CHECKING:
    from motor.core import AgnosticClient
 
client: "AgnosticClient" = motor.motor_asyncio.AsyncIOMotorClient("localhost", 27017)
db_name: str = Path(__file__).parent.parent.name.replace("-", "_")
database = client[db_name]

2. 启动服务器时，挂载数据库连接实例（app/main.py)

from contextlib import asynccontextmanager
from fastapi import FastAPI
from db import database
 
@asynccontextmanager
async def lifespan(app: FastAPI):
    app.state.db = database
    yield
 
 
app = FastAPI(lifespan=lifespan)

3. 根据用户传入的id，查询数据库，返回json格式的数据给用户

from bson.objectid import ObjectId
from fastapi import Request
 
 
@app.get("/items/{id}")
async def item_data(request: Request, id: str) -> dict:
    collection = request.app.state.db['item']
    obj = await collection.find_one({"_id": ObjectId(id)})
    data = {'id': str(obj['_id']), 'name': obj['name']} 
    return data

4. 增删改

# 增
data = {'name': 'xx', 'description': None}
inserted = await collection.insert_one(data)
object_id: str = str(inserted.inserted_id)
 
# 改
data = {'name': 'new_name'}
await collection.update_one({"_id": ObjectId(id)}, {"$set": data})
 
# 删
await collection.delete_one({"_id": ObjectId(id)})
 
# 查询所有记录
objs = []
async for obj in self.collection.find():
    objs.append(obj)