Flask 无法连接到 RDS MySQL

Question

I used flask-sqlalchemy with PostgreSQL. Now, I switched to RDS MySQL, so I changed SQLALCHEMY_DATABASE_URI form

app.config['SQLALCHEMY_DATABASE_URI'] = 'postgres://**************'

to

app.config['SQLALCHEMY_DATABASE_URI'] = "mysql+pymysql://{username}:{password}@{endpoint}:{port}?charset=utf8"

after this, I initialize app like this

from flask import Flask, render_template, request, logging, Response, redirect, flash, jsonify
from flask_cors import CORS
from flask_sqlalchemy import SQLAlchemy
from flask_marshmallow import Marshmallow

app = Flask(__name__)

db = SQLAlchemy(app)
ma = Marshmallow(app)

class User(db.Model):
    __tablename__ = 'user'
    id = db.Column(db.String(8),  primary_key=True)
    name = db.Column(db.String, unique=False)
    email = db.Column(db.String, unique=False)

    def __init__(self,params):
        self.id = params['id']
        self.name = params['name']
        self.email = params['email']

class UserSchema(ma.ModelSchema):
    class Meta:
        model = User

@app.route('/get_user', methods=['GET'])
def get_user():
    userid = request.args['id']
    user = User.query.get(userid)
    return user

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

But the app cannot connect to server. (I confirmed username, password, endpoint, port, is correct and connected from mysql workbench)

I read this question. Switching from SQLite to MySQL with Flask SQLAlchemy so I installed pymysql, but it didn't work.

When my app tried to connect db, this error message is shown. it seems that psycopg2 is called although I'm using mysql.

Could you please give me some advise?

psycopg2.ProgrammingError: invalid dsn: invalid connection option "mysql+pymysql://mysql+pymysql://{username}:{password}{endpoint}:{port}?charset"

Answer 1

该错误消息建议使用调试器断点或仅通过打印来检查您的连接字符串。

print(app.config['SQLALCHEMY_DATABASE_URI'])

Answer 2

它可能是 uri 格式：MySQL 中的“dialect+driver://username:password@host:port/database” “mysql://username:password@localhost:####/mydatabase” https://flask- sqlalchemy.palletsprojects.com/en/2.x/config/#connection-uri-format