Python使用flask框架操作sqlite3的两种方式

import sqlite3
from flask import Flask,request,jsonify
app = Flask(__name__)
DATABASE_URI = ":memory:"
# 创建表格、插入数据
@app.before_first_request
def create_db():
  # 连接
  conn = sqlite3.connect(DATABASE_URI)
  c = conn.cursor()
  # 创建表
  c.execute('''DROP TABLE IF EXISTS user''')
  c.execute('''CREATE TABLE user (id INTEGER PRIMARY KEY AUTOINCREMENT,name TEXT,email TEXT)''')
  # 数据
  # 格式：用户名,邮箱
  purchases = [('admin','admin@example.com'),('guest1','guest1@example.com'),('guest2','guest2@example.com'),('guest3','guest3@example.com'),('guest4','guest4@example.com')]
  # 插入数据
  c.executemany('INSERT INTO user(name,email) VALUES (?,?)',purchases)
  # 提交！！！
  conn.commit()
  # 关闭
  conn.close()
def get_db():
  db = sqlite3.connect(DATABASE_URI)
  db.row_factory = sqlite3.Row
  return db
def query_db(query,args=(),one=False):
  db = get_db()
  cur = db.execute(query,args)
  db.commit()
  rv = cur.fetchall()
  db.close()
  return (rv[0] if rv else None) if one else rv
@app.route("/user")
def users():
  res = query_db("SELECT * FROM user WHERE id <= ?",args=(6,))
  return "<br>".join(["{0}: {1}".format(user[1],user[2]) for user in res])
@app.route("/user/<int:id>")
def user(name):
  res = query_db("SELECT * FROM user WHERE id=?",args=(id,)) #不妨设定：第一次只返回6个数据
  return jsonify(id = res[1],name = res[2],email = res[3]) # 返回json格式
if __name__ == "__main__":
  app.run(debug=True)

# flask_sqlalchemy.py
from flask import Flask
from flask_sqlalchemy import SQLAlchemy
app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite://'
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = True
db = SQLAlchemy(app)
# 定义ORM
class User(db.Model):
  id = db.Column(db.Integer,primary_key=True)
  name = db.Column(db.String(80),unique=True)
  email = db.Column(db.String(120),unique=True)
  def __init__(self,name,email):
    self.name = name
    self.email = email
  def __repr__(self):
    return '<User %r>' % self.name
# 创建表格、插入数据
@app.before_first_request
def create_db():
  # Recreate database each time for demo
  #db.drop_all()
  db.create_all()
  admin = User('admin','admin@example.com')
  db.session.add(admin)
  guestes = [User('guest1',User('guest2',User('guest3',User('guest4','guest4@example.com')]
  db.session.add_all(guestes)
  db.session.commit()
# 查询
@app.route('/user')
def users():
  users = User.query.all()
  return "<br>".join(["{0}: {1}".format(user.name,user.email) for user in users])
# 查询
@app.route('/user/<int:id>')
def user(id):
  user = User.query.filter_by(id=id).one()
  return "{0}: {1}".format(user.name,user.email)
# 运行
if __name__ == '__main__':
  app.run('127.0.0.1',5000)