密码错误消息框答案

【问题标题】：Incorrect password message box密码错误消息框
【发布时间】：2022-01-24 07:06:19
【问题描述】：

import mysql.connector
from tkinter import messagebox

from mysql.connector import Error, InternalError

logman = mysql.connector.connect(host = 'localhost',user = 'root', passwd = '12345678', database = 'basictest')

logwife = logman.cursor(buffered=True)

def wxy(use,pas):
    logboy = ('SELECT Username, Password FROM patient WHERE Password =' + str(pas))

    logwife.execute(logboy)

    x = list(logwife.fetchone())

    print(x)

    if x[0] == use:
        messagebox.showinfo('success','You have successfully Logged in')

    else:
        messagebox.showerror('Failed','Wrong Credentials')

我想这样做，以便在密码错误时显示一个消息框。但是我抛出一个错误

【问题讨论】：

错误是什么？

标签： python tkinter

【解决方案1】：

最终的SQL语句无效，例如pas的值为"pass"，那么最终的SQL语句为：

SELECT Username, Password FROM patient WHERE Password = pass

最好使用占位符。

还要检查是否返回记录，否则x = list(logwife.fetchone())会抛出异常。

以下是更新后的wxy()：

def wxy(use, pas):
    # use placeholder
    logboy = 'SELECT Username, Password FROM patient WHERE Password = %s'
    logwife.execute(logboy, (str(pas),)) # 2nd argument must be tuple or list
    x = logwife.fetchone()
    print(x)

    # better check whether x is None or not before using it
    if x is not None and x[0] == use:
        messagebox.showinfo('success', 'You have successfully Logged in')
    else:
        messagebox.showerror('Failed', 'Wrong Credentials')

我建议在 SQL 中检查用户名和密码：

def wxy(use, pas):
    logboy = 'SELECT 1 FROM patient WHERE Username = %s and Password = %s'
    logwife.execute(logboy, (use, pas))
    x = logwife.fetchone()
    print(x)
    if x is not None:
        messagebox.showinfo('success','You have successfully Logged in')
    else:
        messagebox.showerror('Failed','Wrong Credentials')

请注意，出于安全考虑，不建议将纯文本密码存储在数据库中。

【讨论】：

【解决方案2】：

这些代码行给出了你想要的错误。

else 可能有问题

from tkinter import messagebox

messagebox.showerror("Title", "Message")

【讨论】：