Flask SQLAlchemy 和蓝图

Question

我还在学习烧瓶，我用 SQLAlchemy 创建了一个 restful API。该应用程序越来越大，我想将其拆分为多个文件。当我将路由部分与主文件分开时，应用程序开始抱怨找不到 SQL 模块。我已将所有导入添加到路由文件中，但似乎也无济于事。我得到的错误是：

模块> Session.configure(绑定=引擎) NameError：名称 'engine' 未定义

如何让 Alchemy 模块与 admin.py 对话？

app
  app.py
  admin
    __init__.py
    admin.py
    
######################## admin.py  ########################
from flask import Flask, request, jsonify, Blueprint, render_template
import sqlalchemy
from sqlalchemy.ext.declarative import declarative_base
from flask_sqlalchemy import SQLAlchemy
from flask_marshmallow import Marshmallow
import os
import json
import logging

admin = Blueprint("admin", __name__)

#initialize Session
Session = sqlalchemy.orm.sessionmaker()
Session.configure(bind=engine)
session = Session()


employee_schema = EmployeeSchema()


#create Employee
@admin.route('/', methods=['POST'])
def add_employee():
..........

#Get Employee
@admin.route('/', defaults={'id': None}, methods=['GET'])
@admin.route('/<id>', methods=['GET'])
..........

#Delete Employee
@admin.route('/<id>', methods=['DELETE'])
def delete_employee(id):
..........

#update Employee
@admin.route('/<id>', methods=['PUT'])
def update_employee(id):
..........


######################## app.py  ########################

from flask import Flask, request, jsonify
import sqlalchemy
from sqlalchemy.ext.declarative import declarative_base
from flask_sqlalchemy import SQLAlchemy
from flask_marshmallow import Marshmallow
import os
import json
import logging
from admin.admin import admin



#Init app
app = Flask(__name__)
#Allows URL's to be with a trailing / or not
app.url_map.strict_slashes = False
app.register_blueprint(admin, url_prefix="/")

#Gets password info from json file
..........

# Define the MariaDB engine using MariaDB Connector/Python
engine = sqlalchemy.create_engine(f"mariadb+pymysql://{DB_USER}:{DB_PASS}@{DB_HOST}:{DB_PORT}/{DB}")

Base = declarative_base()

class Employee(Base):

   __tablename__ = 'employees'
   id = sqlalchemy.Column(sqlalchemy.Integer, primary_key=True)
   firstname = sqlalchemy.Column(sqlalchemy.String(length=100))
   lastname = sqlalchemy.Column(sqlalchemy.String(length=100))
   active = sqlalchemy.Column(sqlalchemy.Boolean, default=True)
   
Base.metadata.create_all(engine)

#initialize Session
Session = sqlalchemy.orm.sessionmaker()
Session.configure(bind=engine)
session = Session()

Answer 1

我想你的错误可以追溯到 admin.py，因为你想在其中使用 engine 再次初始化会话，这在 admin.py 中是未知的。一个可能的解决方案是从 app.py.

导入 engine

Answer 2

找到解决方法。我在文件夹中创建了一个 init 文件，现在可以使用了。

Flask SQLAlchemy 和蓝图

Flask SQLAlchemy and Blueprints

python

sqlalchemy

flask