第七章 FastAPI的数据库操作和多应用的目录结构设计

Author: liaogx

coronavirus.sqlite3

@@ -0,0 +1,39 @@
+#!/usr/bin/python3
+# -*- coding:utf-8 -*-
+# __author__ = '__Jack__'
+
+from sqlalchemy.orm import Session
+
+from coronavirus import models, schemas
+
+
+def get_city(db: Session, city_id: int):
+    return db.query(models.City).filter(models.City.id == city_id).first()
+
+
+def get_city_by_name(db: Session, name: str):
+    return db.query(models.City).filter(models.City.province == name).first()
+
+
+def get_cities(db: Session, skip: int = 0, limit: int = 10):
+    return db.query(models.City).offset(skip).limit(limit).all()
+
+
+def create_city(db: Session, city: schemas.CreateCity):
+    db_city = models.City(**city.dict())
+    db.add(db_city)
+    db.commit()
+    db.refresh(db_city)
+    return db_city
+
+
+def get_data(db: Session, skip: int = 0, limit: int = 10):
+    return db.query(models.Data).offset(skip).limit(limit).all()
+
+
+def create_city_data(db: Session, data: schemas.CreateData, city_id: int):
+    db_data = models.Data(**data.dict(), city_id=city_id)
+    db.add(db_data)
+    db.commit()
+    db.refresh(db_data)
+    return db_data

coronavirus/crud.py

@@ -2,74 +2,22 @@
 # -*- coding:utf-8 -*-
 # __author__ = '__Jack__'
 
-from sqlalchemy import create_engine, Column, String, Integer, BigInteger, Date, DateTime, ForeignKey, func
+from sqlalchemy import create_engine
 from sqlalchemy.ext.declarative import declarative_base
-from sqlalchemy.orm import sessionmaker, relationship
+from sqlalchemy.orm import sessionmaker
 
-SQLALCHEMY_DATABASE_URL = 'sqlite:///./coronavirus.db'
+SQLALCHEMY_DATABASE_URL = 'sqlite:///./coronavirus.sqlite3'
 # SQLALCHEMY_DATABASE_URL = "postgresql://username:password@host:port/database_name"  # MySQL或PostgreSQL的连接方法
 
 engine = create_engine(
     # echo=True表示引擎将用repr()函数记录所有语句及其参数列表到日志
-    # 由于SQLAlchemy是多线程，指定check_same_thread=False来让建立的对象任意线程都可使用
+    # 由于SQLAlchemy是多线程，指定check_same_thread=False来让建立的对象任意线程都可使用。这个参数只在用SQLite数据库时设置
     SQLALCHEMY_DATABASE_URL, encoding='utf-8', echo=True, connect_args={'check_same_thread': False}
 )
 
-# 在SQLAlchemy中，CRUD都是通过会话(session)进行的，所以我们必须要先创建会话
+# 在SQLAlchemy中，CRUD都是通过会话(session)进行的，所以我们必须要先创建会话，每一个SessionLocal实例就是一个数据库session
 # flush()是指发送数据库语句到数据库，但数据库不一定执行写入磁盘；commit()是指提交事务，将变更保存到数据库文件
 SessionLocal = sessionmaker(bind=engine, autoflush=False, autocommit=False, expire_on_commit=True)
 
 # 创建基本映射类
 Base = declarative_base(bind=engine, name='Base')
-
-
-class City(Base):
-    __tablename__ = 'city'
-
-    id = Column(Integer, primary_key=True, index=True, autoincrement=True)
-    province = Column(String(100), unique=True, nullable=False, comment='省/直辖市')
-    country = Column(String(100), nullable=False, comment='国家')
-    country_code = Column(String(100), nullable=False, comment='国家代码')
-    country_population = Column(BigInteger, nullable=False, comment='国家人口')
-    data = relationship('Data', backref='city')  # 'Data'是关联的类名；backref来指定反向访问的属性名称
-
-    created_at = Column(DateTime, server_default=func.now(), comment='创建时间')
-    updated_at = Column(DateTime, server_default=func.now(), onupdate=func.now(), comment='更新时间')
-
-    __mapper_args__ = {"order_by": country_code}  # 默认是正序，倒序加上.desc()方法
-
-    def __repr__(self):
-        return f'{self.country}_{self.province}'
-
-
-class Data(Base):
-    __tablename__ = 'data'
-
-    id = Column(Integer, primary_key=True, index=True, autoincrement=True)
-    city_id = Column(Integer, ForeignKey('city.id'), ondelete='CASCADE', comment='所属省/直辖市')  # ForeignKey里的字符串格式不是类名.属性名，而是表名.字段名
-    date = Column(Date, nullable=False, comment='数据日期')
-    confirmed = Column(BigInteger, default=0, nullable=False, comment='确诊数量')
-    deaths = Column(BigInteger, default=0, nullable=False, comment='死亡数量')
-    recovered = Column(BigInteger, default=0, nullable=False, comment='痊愈数量')
-    city = relationship('City', backref='data')  # 'City'是关联的类名；backref来指定反向访问的属性名称
-
-    created_at = Column(DateTime, server_default=func.now(), comment='创建时间')
-    updated_at = Column(DateTime, server_default=func.now(), onupdate=func.now(), comment='更新时间')
-
-    __mapper_args__ = {"order_by": confirmed}
-
-    def __repr__(self):
-        return f'{repr(self.date)}：确诊{self.confirmed}例'
-
-
-""" 附上三个SQLAlchemy教程
-
-SQLAlchemy的基本操作大全 
-    http://www.taodudu.cc/news/show-175725.html
-
-Python3+SQLAlchemy+Sqlite3实现ORM教程 
-    https://www.cnblogs.com/jiangxiaobo/p/12350561.html
-
-SQLAlchemy基础知识 Autoflush和Autocommit
-    https://zhuanlan.zhihu.com/p/48994990
-"""

coronavirus/database.py

@@ -2,115 +2,63 @@
 # -*- coding:utf-8 -*-
 # __author__ = '__Jack__'
 
-from fastapi import Request, Depends, BackgroundTasks, APIRouter
-from pydantic import BaseModel
-from sqlalchemy.orm import Session
-
-
-# from coronavirus.database import engine, SessionLocal, Base
-
+from typing import List
 
+from fastapi import APIRouter, Depends, HTTPException
 from fastapi.staticfiles import StaticFiles
 from fastapi.templating import Jinja2Templates
+from sqlalchemy.orm import Session
 
+from coronavirus import crud, schemas
+from coronavirus.database import engine, Base, SessionLocal
 
 application = APIRouter()
 
-
+# mount表示将某个目录下一个完全独立的应用挂载过来，这个不会在API交互文档中显示
 application.mount('/static', StaticFiles(directory='./coronavirus/static'), name='static')
 templates = Jinja2Templates(directory='./coronavirus/templates')
 
+Base.metadata.create_all(bind=engine)
+
+
+def get_db():
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()
+
+
+@application.post("/create_city", response_model=schemas.ReadCity)
+def create_city(city: schemas.CreateCity, db: Session = Depends(get_db)):
+    db_city = crud.get_city_by_name(db, name=city.province)
+    if db_city:
+        raise HTTPException(status_code=400, detail="City already registered")
+    return crud.create_city(db=db, city=city)
+
+
+@application.get("/get_city/{city}", response_model=schemas.ReadCity)
+def get_city(city: str, db: Session = Depends(get_db)):
+    db_city = crud.get_city_by_name(db, name=city)
+    if db_city is None:
+        raise HTTPException(status_code=404, detail="City not found")
+    return db_city
+
+
+@application.get("/get_cities", response_model=List[schemas.ReadCity])
+def get_cities(skip: int = 0, limit: int = 100, db: Session = Depends(get_db)):
+    cities = crud.get_cities(db, skip=skip, limit=limit)
+    return cities
+
+
+@application.post("/create_data", response_model=schemas.ReadData)
+def create_data_for_city(city: str, data: schemas.CreateData, db: Session = Depends(get_db)):
+    db_city = crud.get_city_by_name(db, name=city)
+    data = crud.create_city_data(db=db, data=data, city_id=db_city.id)
+    return data
+
 
-# Base.metadata.create_all(bind=engine)
-
-
-@application.get("/")
-async def index(request: Request):
-    return templates.TemplateResponse("index.html", {"request": request, "title": "This is title"})  # {"request": request}是必须的
-
-
-@application.get("/coronavirus")
-async def coronavirus():
-    """This is a simple tutorial"""
-    return {"message": {"This is another route"}}
-
-
-# class StockRequest(BaseModel):
-#     symbol: str
-#
-#
-# def get_db():
-#     try:
-#         db = SessionLocal()
-#         yield db
-#     finally:
-#         db.close()
-#
-#
-# @application.get("/")
-# def home(request: Request, forward_pe=None, dividend_yield=None, ma50=None, ma200=None, db: Session = Depends(get_db)):
-#     """
-#     displays the stock screener dashboard / homepage
-#     :return:
-#     """
-#     stocks = db.query(Stock)
-#
-#     if forward_pe:
-#         stocks = stocks.filter(Stock.forward_pe < forward_pe)
-#
-#     if dividend_yield:
-#         stocks = stocks.filter(Stock.dividend_yield > dividend_yield)
-#
-#     if ma50:
-#         stocks = stocks.filter(Stock.price > Stock.ma50)
-#
-#     if ma200:
-#         stocks = stocks.filter(Stock.price > Stock.ma200)
-#
-#     return templates.TemplateResponse("home.html", {
-#         "request": request,
-#         "stocks": stocks
-#     })
-#
-#
-# def fetch_stock_data(id_: int):
-#     """
-#     fetch data from yahoo finance
-#     :param id_:
-#     :return:
-#     """
-#     db = SessionLocal()
-#     stock = db.query(Stock).filter(Stock.id == id_).first()
-#
-#     yahoo_data = yf.Ticker(stock.symbol)
-#
-#     stock.ma50 = yahoo_data.info["fiftyDayAverage"]
-#     stock.ma200 = yahoo_data.info["twoHundredDayAverage"]
-#     stock.price = yahoo_data.info["previousClose"]
-#     stock.forward_pe = yahoo_data.info["forwardPE"]
-#     stock.forward_eps = yahoo_data.info["forwardEps"]
-#     if yahoo_data.info["dividendYield"]:
-#         stock.dividend_yield = yahoo_data.info["dividendYield"] * 100
-#
-#     db.add(stock)
-#     db.commit()
-#
-#
-# @application.post("/stock")
-# async def create_stock(stock_request: StockRequest, background_tasks: BackgroundTasks, db: Session = Depends(get_db)):
-#     """
-#     created a stock and stores it in the database
-#     :return:
-#     """
-#     stock = Stock()
-#     stock.symbol = stock_request.symbol
-#
-#     db.add(stock)
-#     db.commit()
-#
-#     background_tasks.add_task(fetch_stock_data, stock.id)
-#
-#     return {
-#         "code": "success",
-#         "message": "stock created"
-#     }
+@application.get("/get_data", response_model=List[schemas.ReadData])
+def get_data(skip: int = 0, limit: int = 100, db: Session = Depends(get_db)):
+    data = crud.get_data(db, skip=skip, limit=limit)
+    return data

coronavirus/main.py

@@ -0,0 +1,60 @@
+#!/usr/bin/python3
+# -*- coding:utf-8 -*-
+# __author__ = '__Jack__'
+
+from sqlalchemy import Column, String, Integer, BigInteger, Date, DateTime, ForeignKey, func
+from sqlalchemy.orm import relationship
+
+from .database import Base
+
+
+class City(Base):
+    __tablename__ = 'city'  # 数据表的表名
+
+    id = Column(Integer, primary_key=True, index=True, autoincrement=True)
+    province = Column(String(100), unique=True, nullable=False, comment='省/直辖市')
+    country = Column(String(100), nullable=False, comment='国家')
+    country_code = Column(String(100), nullable=False, comment='国家代码')
+    country_population = Column(BigInteger, nullable=False, comment='国家人口')
+    data = relationship('Data', back_populates='city')  # 'Data'是关联的类名；back_populates来指定反向访问的属性名称
+
+    created_at = Column(DateTime, server_default=func.now(), comment='创建时间')
+    updated_at = Column(DateTime, server_default=func.now(), onupdate=func.now(), comment='更新时间')
+
+    __mapper_args__ = {"order_by": country_code}  # 默认是正序，倒序加上.desc()方法
+
+    def __repr__(self):
+        return f'{self.country}_{self.province}'
+
+
+class Data(Base):
+    __tablename__ = 'data'
+
+    id = Column(Integer, primary_key=True, index=True, autoincrement=True)
+    city_id = Column(Integer, ForeignKey('city.id'), comment='所属省/直辖市')  # ForeignKey里的字符串格式不是类名.属性名，而是表名.字段名
+    date = Column(Date, nullable=False, comment='数据日期')
+    confirmed = Column(BigInteger, default=0, nullable=False, comment='确诊数量')
+    deaths = Column(BigInteger, default=0, nullable=False, comment='死亡数量')
+    recovered = Column(BigInteger, default=0, nullable=False, comment='痊愈数量')
+    city = relationship('City', back_populates='data')  # 'City'是关联的类名；back_populates来指定反向访问的属性名称
+
+    created_at = Column(DateTime, server_default=func.now(), comment='创建时间')
+    updated_at = Column(DateTime, server_default=func.now(), onupdate=func.now(), comment='更新时间')
+
+    __mapper_args__ = {"order_by": confirmed}
+
+    def __repr__(self):
+        return f'{repr(self.date)}：确诊{self.confirmed}例'
+
+
+""" 附上三个SQLAlchemy教程
+
+SQLAlchemy的基本操作大全 
+    http://www.taodudu.cc/news/show-175725.html
+
+Python3+SQLAlchemy+Sqlite3实现ORM教程 
+    https://www.cnblogs.com/jiangxiaobo/p/12350561.html
+
+SQLAlchemy基础知识 Autoflush和Autocommit
+    https://zhuanlan.zhihu.com/p/48994990
+"""

coronavirus/models.py

@@ -0,0 +1,43 @@
+#!/usr/bin/python3
+# -*- coding:utf-8 -*-
+# __author__ = '__Jack__'
+
+from datetime import date as date_
+from datetime import datetime
+from typing import List
+
+from pydantic import BaseModel
+
+
+class CreateData(BaseModel):
+    date: date_
+    confirmed: int = 0
+    deaths: int = 0
+    recovered: int = 0
+
+
+class CreateCity(BaseModel):
+    province: str
+    country: str
+    country_code: str
+    country_population: int
+    data: List[CreateData] = []
+
+
+class ReadData(CreateData):
+    id: int
+    city_id: int
+    updated_at: datetime
+    created_at: datetime
+
+    class Config:
+        orm_mode = True
+
+
+class ReadCity(CreateCity):
+    id: int
+    updated_at: datetime
+    created_at: datetime
+
+    class Config:
+        orm_mode = True