我想用数据库查询的结果填充 ttk.combobox

Question

我有一个小问题，我需要帮助 with.This 关注点 python ttk.combobox 小部件我是 python 的新手，一周前才开始编码。我有一个由用户填充的数据库 input.This 数据库用于存储用户的库存输入（例如项目、成本、供应商等）。这部分我已经能够做到。

从数据库中，我使用 'for' 循环将每个单独的项目从我的数据库查询中获取到 ttk.combobox 中，以便用户可以进行选择。但是我的问题是，我每次都会出错。我希望组合框显示我的数据库查询中项目列中的所有项目。

从在线资源中，我找到了 ttk.combobox 的示例：

    list = ['shoe', 'toy', 'bag']
    combobox = ttk.Combobox(root)
    combobox['values'] = list

如果我要使用自制列表，这很好用但是，我无法在 python

中使用来自 sqlite3 的查询找到 ttk.combobox 的示例

预先感谢您帮助我解决这个问题。一个如何做的例子以及对我做错了什么的解释将对我有很大帮助。请原谅我的编码风格，我希望随着时间的推移变得更好。

from tkinter import *
from tkinter import ttk
import sqlite3

class Example:
    def __init__(self,master):
     self.master = master
     self.win_label = Label(master, text="New Stock Entry")
     self.win_label.grid(row=0, columnspan=2,)
     self.item_label = Label(master, text="Item Name", fg='black')
     self.item_label.grid(row=1, column=0, sticky=W, padx=5, pady=5)
     self.unitprice_lab = Label(master, text="Unit Price", fg='black')
     self.unitprice_lab.grid(row=2, column=0, sticky=W, padx=5, pady=5)
     self.total_price = Label(master, text="Total Price", fg='black')
     self.total_price.grid(row=3, column=0, sticky=W, padx=5, pady=5)
     self.quantity_lab = Label(master, text="Quantity", fg='black')
     self.quantity_lab.grid(row=4, column=0, sticky=W, padx=5, pady=5)
     self.manufacturer_lab = Label(master,text="Manufacturer", fg='black')
     self.manufacturer_lab.grid(row=5, column=0, sticky=W, padx=5, pady=5)

      ############### Variables to store input ################
     self.item = StringVar()
     self.unitp = IntVar()
     self.unitn = IntVar()
     self.quantity = IntVar()
     self.man = StringVar()

     ############ Widgets############
     self.item_entry = Entry(master, width=25,textvariable=self.item)
     self.item_entry.grid(row=1, column=1, padx=5, pady=5)
     self.unitprice_entry = Entry(master, width=25,textvariable=self.unitp)
     self.unitprice_entry.grid(row=2, column=1, sticky=W, padx=5, pady=5)
     self.total_price_entry = Entry(master,width=25,textvariable=self.unitn)
     self.total_price_entry.grid(row=3, column=1, sticky=W, padx=5, pady=5)
     self.quantity_entry = Entry(master,width=25,textvariable=self.quantity)
     self.quantity_entry.grid(row=4, column=1, sticky=W, padx=5, pady=5)
     self.manufacturer_entry = Entry(master, width=25,textvariable=self.man)
     self.manufacturer_entry.grid(row=5, column=1, sticky=W, padx=5, pady=5)
     # button for save
     self.button_save = Button(master,text="Save",command= self.insert_Dbs)
     self.button_save.grid(row=6, column=1, pady=15, padx=10, sticky=W)

  def second_window(self):  # Second Window to allow user selection
    t = Toplevel()
    t.geometry('350x290')
    t.title('Student Input')

    ############# widgets ###############
    self.label1 = ttk.Label(t, text = 'Student Name')
    self.label1.grid(row =0 , column =0)
    self.label2 = ttk.Label(t, text='Item Collected')
    self.label2.grid(row=0, column=1)
    self.label3 = ttk.Label(t, text='Quantity')
    self.label3.grid(row=0, column=2)
    self.entry1 =ttk.Entry(t, width = 20)
    self.entry1.grid(row =1 , column =0)
    self.entry2 = ttk.Entry(t, width=20)
    self.entry2.grid(row=1, column=2)
    self.comb = ttk.Combobox(t,width = 15).grid(row =1 , column =1)
    self.comb['value'] = self.combo_input


  def insert_Dbs(self): # Function to insert input into database

    self.a1 = self.item.get()
    self.a2 = self.unitp.get()
    self.a3 = self.unitn.get()
    self.a4 = self.quantity.get()
    self.a5 = self.man.get()

    #db = sqlite3.connect('stockdbExample.db')
    '''db.execute('create table stocks (item text '
               ', item_uprice integer,'
               '  item_nprice integer,'
               ' quantity integer,'
               ' manufacturer text )')'''
    db = sqlite3.connect('stockdbExample.db')
    db.execute('insert into stocks (item,'
               ' item_uprice,'
               ' item_nprice,'
               ' quantity,'
               ' manufacturer) values (?, ?, ?, ?,?)',
               (self.a1, self.a2, self.a3, self.a4, self.a5))
    db.commit()
    self.combo_input()
    self.second_window()

  def combo_input(self):
    db = sqlite3.connect('stockdbExample.db')
    cursor = db.execute('select item from stocks')
    for row in cursor.fetchall():
        return row

root = Tk()
c = Example(root)
root.mainloop()

Answer 1

第一：你忘记了()执行函数

self.comb['value'] = self.combo_input()

第二：在 combo_input 里面你使用 return row 所以你 return 只有第一行，仅此而已。

您必须创建包含所有值的 Python 列表，然后 return 它。
它可以是这样的：

def combo_input(self):
    db = sqlite3.connect('stockdbExample.db')
    cursor = db.execute('select item from stocks')

    result = []

    for row in cursor.fetchall():
        result.append(row[0])

    return result

编辑：完整的工作示例：

import tkinter as tk
import tkinter.ttk as ttk
import sqlite3

class Example:

  def __init__(self,master):
     self.master = master

     self.db = sqlite3.connect('stockdbExample.db')

     # use only once
     self.create_db()   

     self.cb = ttk.Combobox(master)
     self.cb.pack()
     self.cb['values'] = self.combo_input()

  def combo_input(self):
    cursor = self.db.cursor()

    cursor.execute('SELECT item FROM stocks')

    data = []

    for row in cursor.fetchall():
        data.append(row[0])

    return data

  def create_db(self):

    cursor = self.db.cursor()
    cursor.execute('CREATE TABLE stocks (item text)')
    cursor.execute('INSERT INTO stocks (item) VALUES("Hello")')
    cursor.execute('INSERT INTO stocks (item) VALUES("World")')
    cursor.execute('INSERT INTO stocks (item) VALUES("Tkinter")')
    cursor.close()

    self.db.commit()

root = tk.Tk()
Example(root)
root.mainloop()

我想用数据库查询的结果填充 ttk.combobox

I want to populate a ttk.combobox with results from database query

sqlite

python-3.x

tkinter

ttk