Flask-MySQLdb raises _mysql_exceptions.ProgrammingError: closing a closed connection

Question

我正在尝试使用 Flask-MySQLdb。每次我转到一个页面时，我都会收到错误 _mysql_exceptions.ProgrammingError: closing a closed connection。为什么这不起作用？

from flask import Flask, render_template, request, json
from flask_mysqldb import MySQL

application = Flask(__name__)
mysql = MySQL(application)

application.config['MYSQL_USER'] = 'root'
application.config['MYSQL_PASSWORD'] = 'password'
application.config['MYSQL_DB'] = 'db name'
application.config['MYSQL_HOST'] = 'localhost'
mysql.init_app(application)

@application.route('/')
def index():
    cur = mysql.connection.cursor()
    cur.execute("SHOW TABLES")
    rv= cur.fetchall()
    return str(rv)

if __name__ == "__main__":
    application.run()

Answer 1

您已在同一个应用程序上初始化扩展程序两次。每次初始化时，它都会注册一个关闭连接的函数。所以第二个函数关闭了一个已经被第一个注册函数关闭的连接。从 MySQL 中删除 application（最好）或删除对 mysql.init_app.

的显式调用

mysql = MySQL()
mysql.init_app(application)

Flask-MySQLdb raises _mysql_exceptions.ProgrammingError: closing a closed connection

Flask-MySQLdb raises _mysql_exceptions.ProgrammingError: closing a closed connection

mysql

mysql-python

flask