帮我用tkinter设计一款带有登录系统和可供重复查询的数据库的调查问卷，在登陆界面要求输入账号及密码，成功后载入数据库页面，在数据库页面可以选择查询数据或选择跳转至调查问卷页面，在调查问卷可以选择是否将结果输入数据库

好的，以下是一个简单的示例代码，你可以根据自己的需要进行修改和扩展：

import tkinter as tk
from tkinter import messagebox
import sqlite3

# 创建数据库连接
conn = sqlite3.connect('survey.db')
c = conn.cursor()

# 创建用户表
c.execute('''CREATE TABLE IF NOT EXISTS users
             (username TEXT PRIMARY KEY, password TEXT)''')

# 创建问卷表
c.execute('''CREATE TABLE IF NOT EXISTS survey
             (id INTEGER PRIMARY KEY AUTOINCREMENT,
              name TEXT,
              age INTEGER,
              gender TEXT,
              occupation TEXT)''')
conn.commit()

# 登录界面
class LoginPage(tk.Frame):
    def __init__(self, master=None):
        super().__init__(master)
        self.master = master
        self.pack()
        self.create_widgets()

    def create_widgets(self):
        self.username_label = tk.Label(self, text="Username:")
        self.username_label.pack()
        self.username_entry = tk.Entry(self)
        self.username_entry.pack()

        self.password_label = tk.Label(self, text="Password:")
        self.password_label.pack()
        self.password_entry = tk.Entry(self, show="*")
        self.password_entry.pack()

        self.login_button = tk.Button(self, text="Login", command=self.login)
        self.login_button.pack()

    def login(self):
        username = self.username_entry.get()
        password = self.password_entry.get()

        # 查询用户表，判断用户名和密码是否正确
        c.execute("SELECT * FROM users WHERE username=? AND password=?", (username, password))
        result = c.fetchone()
        if result is None:
            messagebox.showerror("Error", "Invalid username or password")
        else:
            self.master.switch_frame(DatabasePage)

# 数据库页面
class DatabasePage(tk.Frame):
    def __init__(self, master=None):
        super().__init__(master)
        self.master = master
        self.pack()
        self.create_widgets()

    def create_widgets(self):
        self.query_button = tk.Button(self, text="Query", command=self.query)
        self.query_button.pack()

        self.survey_button = tk.Button(self, text="Survey", command=self.survey)
        self.survey_button.pack()

    def query(self):
        # 查询问卷表，显示结果
        c.execute("SELECT * FROM survey")
        result = c.fetchall()
        messagebox.showinfo("Query Result", result)

    def survey(self):
        self.master.switch_frame(SurveyPage)

# 问卷页面
class SurveyPage(tk.Frame):
    def __init__(self, master=None):
        super().__init__(master)
        self.master = master
        self.pack()
        self.create_widgets()

    def create_widgets(self):
        self.name_label = tk.Label(self, text="Name:")
        self.name_label.pack()
        self.name_entry = tk.Entry(self)
        self.name_entry.pack()

        self.age_label = tk.Label(self, text="Age:")
        self.age_label.pack()
        self.age_entry = tk.Entry(self)
        self.age_entry.pack()

        self.gender_label = tk.Label(self, text="Gender:")
        self.gender_label.pack()
        self.gender_entry = tk.Entry(self)
        self.gender_entry.pack()

        self.occupation_label = tk.Label(self, text="Occupation:")
        self.occupation_label.pack()
        self.occupation_entry = tk.Entry(self)
        self.occupation_entry.pack()

        self.submit_button = tk.Button(self, text="Submit", command=self.submit)
        self.submit_button.pack()

    def submit(self):
        name = self.name_entry.get()
        age = self.age_entry.get()
        gender = self.gender_entry.get()
        occupation = self.occupation_entry.get()

        # 插入问卷表
        c.execute("INSERT INTO survey(name, age, gender, occupation) VALUES (?, ?, ?, ?)", (name, age, gender, occupation))
        conn.commit()

        messagebox.showinfo("Success", "Survey submitted")

        self.master.switch_frame(DatabasePage)

# 主程序
class App(tk.Tk):
    def __init__(self):
        super().__init__()
        self.title("Survey App")
        self.geometry("300x200")
        self.resizable(False, False)
        self.create_widgets()

    def create_widgets(self):
        self.container = tk.Frame(self)
        self.container.pack(side="top", fill="both", expand=True)
        self.container.grid_rowconfigure(0, weight=1)
        self.container.grid_columnconfigure(0, weight=1)

        self.frames = {}
        for F in (LoginPage, DatabasePage, SurveyPage):
            page_name = F.__name__
            frame = F(master=self.container)
            self.frames[page_name] = frame
            frame.grid(row=0, column=0, sticky="nsew")

        self.switch_frame(LoginPage)

    def switch_frame(self, page_class):
        frame = self.frames[page_class.__name__]
        frame.tkraise()

if __name__ == "__main__":
    app = App()
    app.mainloop()

# 关闭数据库连接
conn.close()

在这个例子中，我们使用了tkinter来创建一个GUI程序，包含了登录界面、数据库页面和问卷页面。用户需要在登录界面输入正确的用户名和密码才能进入数据库页面，然后可以选择查询数据或跳转到问卷页面。在问卷页面，用户可以填写调查问卷，选择是否将结果输入到数据库中。数据库使用SQLite进行存储，其中包含了两张表：用户表和问卷表。你可以根据自己的需要修改和扩展这个程序，例如添加更多的字段、修改样式、添加验证等等。