问题描述
我是REST API的新手,并开始使用Flask,sqlAlchemy和棉花糖构建第一个REST API应用程序。这是我的PORT
文件:
app.py
要生成sqlite数据库,我必须打开python交互式shell,然后必须执行以下操作:
from flask import Flask,request,jsonify
from flask_sqlalchemy import sqlAlchemy
from flask_marshmallow import Marshmallow
import os
# Initialize App
app = Flask(__name__)
basedir = os.path.abspath(os.path.dirname(__file__))
# Database Setup
app.config['sqlALCHEMY_DATABASE_URI'] = 'sqlite:///' + os.path.join(basedir,'db.sqlite')
app.config['sqlALCHEMY_TRACK_MODIFICATIONS'] = False
# Init db
db = sqlAlchemy(app)
# Init marshmallow
ma = Marshmallow(app)
# Product Class/Model
class Product(db.Model):
id = db.Column(db.Integer,primary_key=True)
name = db.Column(db.String(100),unique=True)
description = db.Column(db.String(200))
price = db.Column(db.Float)
qty = db.Column(db.Integer)
def __init__(self,name,description,price,qty):
self.name = name
self.description = description
self.price = price
self.qty = qty
# Product Schema
class ProductSchema(ma.Schema):
class Meta:
fields = ('id','name','description','price','qty')
# Init Schema
product_schema = ProductSchema()
products_schema = ProductSchema(many=True)
# Create Product
@app.route('/product',methods=['POST'])
def add_product():
name = request.json['name']
description = request.json['description']
price = request.json['price']
qty = request.json['qty']
new_product = Product(name,qty)
db.session.add(new_product)
db.session.commit()
return product_schema.jsonify(new_product)
# Get All Products
@app.route('/receive',methods=['GET'])
def get_products():
all_products = Product.query.all()
result = products_schema.dump(all_products)
return jsonify(result)
# Run the Server
if __name__ == '__main__':
app.run(debug=True)
但是我必须从from app import db
db.create_all()
本身生成数据库,所以我在app.py
内插入了相同的命令,但这给了我错误:
app.py
如何从OperationalError: (sqlite3.OperationalError) no such table: product
生成数据库?
解决方法
您要将db.create_all()放在哪里?该错误可能只是放置的结果。当我将您的代码复制并粘贴到PyCharm(运行Python 3.7)中时,它会在我放置时创建数据库。
$('input[name="topic[tags]"]')
立即之前
db.create_all()
如果您在实例化db对象之前尝试运行db.create_all(),则将引发错误,因为db还不存在。
您完全不需要使用“从应用程序导入数据库”,因为db对象已声明为最高。