FastAPI+SQLAlchemy数据库连接
配置数据库连接
from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker
DATABASE_URL = "mysql+pymysql://root:7997@localhost/fastapidemo"
engine = create_engine(
DATABASE_URL,
pool_size=10,
max_overflow=20,
pool_timeout=30,
pool_recycle=1800,
)
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
创建表模型
from sqlalchemy import Column, Integer, String, ForeignKey, Table
from sqlalchemy.orm import DeclarativeBase, relationship
class Base(DeclarativeBase):
__abstract__ = True
@classmethod
def get_all(cls, session):
return session.query(cls).all()
book_press = Table('book_press', Base.metadata,
Column('book_id', Integer, ForeignKey('book.id'), primary_key=True),
Column('press_id', Integer, ForeignKey('press.id'), primary_key=True))
class Book(Base):
__tablename__ = 'book'
id = Column(Integer, primary_key=True, autoincrement=True)
title = Column(String(15), nullable=False, unique=True)
author_id = Column(Integer, ForeignKey('author.id'))
author = relationship('Author', backref='books', cascade='all,delete')
press = relationship('Press', backref='books', secondary=book_press)
class Author(Base):
__tablename__ = 'author'
id = Column(Integer, primary_key=True, autoincrement=True)
name = Column(String(15), nullable=False, unique=True)
age = Column(Integer, nullable=False)
class Press(Base):
__tablename__ = 'press'
id = Column(Integer, primary_key=True, autoincrement=True)
name = Column(String(15), nullable=False, unique=True)
if __name__ == '__main__':
from db import engine
Base.metadata.create_all(engine)
创建alembic迁移文件
安装+初始化
pip install alembic
alembic init alembic
编辑env.py
from logging.config import fileConfig
from sqlalchemy import engine_from_config
from sqlalchemy import pool
from alembic import context
from module import Base, Book, Author, Press
config = context.config
target_metadata = Base.metadata
编辑alembic.ini
# alembic.ini
sqlalchemy.url = mysql+pymysql://root:7997@localhost/fastapidemo
迁移数据库
alembic revision --autogenerate
alembic upgrade head
视图函数查询
from fastapi import FastAPI, Request, Depends
from pydantic import BaseModel
from sqlalchemy.orm import Session
from db import SessionLocal
from orm import Author
app = FastAPI()
session = SessionLocal()
def get_db():
db = SessionLocal()
try:
yield db
finally:
db.close()
class Item(BaseModel):
pass
@app.get("/api/")
async def root(db: Session = Depends(get_db)):
res = db.query(Author).all()
res2 = Author.get_all(db)
print(res[0].name)
print(res2[0].name)
return {f"作者名:{res[0].name},{res2[0].name}"}