flask使用现有的数据表、在网页中显示数据

参考网站：https://blog.csdn.net/qq_42359659/article/details/102983515?utm_medium=distribute.pc_relevant_t0.none-task-blog-BlogCommendFromMachineLearnPai2-1.nonecase&depth_1-utm_source=distribute.pc_relevant_t0.none-task-blog-BlogCommendFromMachineLearnPai2-1.nonecase

config.py文件
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host = "127.0.0.1"
port = "3306"
database = "myself_weather"
username = "root"
password = "123456"
DB = 'mysql+pymysql://{}:{}@{}:{}/{}?charset=utf8'.format(username,password,host,port,database)
SQLALCHEMY_DATABASE_URI = DB

#设置数据库追踪信息,压制警告
SQLALCHEMY_TRACK_MODIFICATIONS = True

exam.py文件
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from flask import Flask, render_template, redirect, url_for, request,session
from flask_sqlalchemy import SQLAlchemy
import config

app = Flask(__name__)

app.config.from_object(config)
# 创建SQLAlchemy类对象,关联app
db = SQLAlchemy(app)

    # Grade 类名一般和表名一样，不过要大写

class Data_weather(db.Model):
    # grade 是表名
    __tablename__ = "data_weather"

    # 参数1:表示整数类型,  参数2:表示主键
    id = db.Column(db.Integer, primary_key=True)
    city = db.Column(db.String(50), nullable=False)
    ymd = db.Column(db.String(50), nullable=False)
    tianqi = db.Column(db.String(50), nullable=False)
    bWendu = db.Column(db.String(50), nullable=False)
    yWendu = db.Column(db.String(50), nullable=False)
    fenli = db.Column(db.String(50), nullable=False)
    fenxiang = db.Column(db.String(50), nullable=False)
    yer = db.Column(db.String(50), nullable=False)
    month = db.Column(db.String(50), nullable=False)

#查询地方是咸阳的
user = db.session.query(Data_weather).filter(Data_weather.city=="咸阳").all()
for i in user:
    print(i.id,i.city,i.ymd)



if __name__ == '__main__':
    app.run(debug=True)