我想填充一个ttk.combobox与数据库查询结果

Question

我有一个小问题，我需要帮助.This关心python ttk.combobox部件 我是刚刚开始编码一个星期前的python。 我有一个由用户输入填充的数据库。这个数据库存储用户的股票输入（例如物品，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'循环将我的数据库查询中的每个单独项目都转换为ttk.combobox，以便用户进行选择。 但是我的问题是，我每次都遇到错误。 我希望组合框从我的数据库查询中显示项目列中的所有项目。

线上来源，我发现了ttk.combobox一个例子：

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

这工作得很好，如果我使用自制名单 但是，我找不到一个例子一个ttk.combobox使用python中sqlite3的查询

非常感谢您帮助我解决这个问题。 如何做到这一点的一个例子，并解释我做错了什么将帮助我很多。 请原谅我组织糟糕的编码风格，我希望随着时间的推移可以更好地进行编程。

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：你忘了()执行功能

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

二：内combo_input您使用return row所以你只返回第一行，仅此而已。

您必须创建包含所有值的Python列表，然后将其返回。
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，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()