的Python的Tkinter保存列表框項目訂購到SQLite數據庫

Question

我有一個拖和下降列表框（found here），讓用戶拖動/移動項目向上或向下重新排序它們。

我有一個db.sqlite文件看起來像這樣開始：

>>> make_df() 
    ordering   fruit 
0   0   apples 
1   1  oranges 
2   2 blueberries 
3   3  watermelon 
4   4  cantaloupe 
5   5   pears 
6   6 pomegranate 
7   7 raspberries 
8   8 blackberries 
9   9 boysenberries 
10  10  nectarines 

我所試圖做的是在ListBox周圍重新排列項目，並依次保存到數據庫中，所以當我重新啓動程序中，這些項目與我上次使用它的順序相同。

問題： 我每次重新啓動程序，從列表框中的項目總是以相同的順序。但是，當我重新排序項目時，然後運行make_df，它查看數據庫以查看排序並返回一個數據幀，它顯示數據庫在該會話期間更新。 這只是不能永久保存，這是我無法弄清楚的。

import tkinter as tk 
import pandas as pd 
import sqlite3 
root = tk.Tk() 

def make_sqlite_db_for_stackoverflow(): 
    connection = sqlite3.connect('db.sqlite') 
    db_file_name = 'db.sqlite' 
    df = pd.DataFrame(
    [(0, 'apples'), (1, 'oranges'), (2, 'blueberries'), (3, 'watermelon'), 
    (4, 'cantaloupe'), (5, 'pears'), (6, 'pomegranate'), (7, 'raspberries'), 
    (8, 'blackberries'), (9, 'boysenberries'), (10, 'nectarines')], 
    columns=['ordering', 'fruit'] 
    ) 
    df.to_sql('columns', connection, index=False, if_exists='replace') 
    connection.close() 

make_sqlite_db_for_stackoverflow() 

def make_df(): 
    print(pd.DataFrame(sqlite3.connect('db.sqlite').cursor().execute(
    'SELECT * FROM columns ORDER BY "ordering";').fetchall(), columns=['ordering', 'fruit'])) 

class Drag_and_Drop_Listbox(tk.Listbox): 
    """ A tk listbox with drag'n'drop reordering of entries. """ 
    def __init__(self, master, **kw): 
    kw['selectmode'] = tk.EXTENDED 
    tk.Listbox.__init__(self, master, kw) 
    self.bind('<Button-1>', self.setCurrent) 
    self.bind('<B1-Motion>', self.shiftSelection) 
    self.curIndex = None 
    def setCurrent(self, event): 
    self.curIndex = self.nearest(event.y) 
    def shiftSelection(self, event): 
    i = self.nearest(event.y) 
    if i < self.curIndex: 
     x = self.get(i) 
     self.delete(i) 
     self.insert(i+1, x) 
     self.curIndex = i 
    elif i > self.curIndex: 
     x = self.get(i) 
     self.delete(i) 
     self.insert(i-1, x) 
     self.curIndex = i 

def update_ordering(*args): 
    connect = sqlite3.connect('db.sqlite') 
    cursor = connect.cursor() 
    field_ordering = [(order,fruit) for order,fruit in enumerate(ddlistbox.get(0, 'end'))] 
    print(field_ordering) 
    for field in field_ordering: 
    cursor.execute("UPDATE columns SET 'ordering'="+str(field[0])+" WHERE fruit='"+field[1]+"';") 
    connect.commit() 
    connect.close() 
    print(ddlistbox.curselection()) 

scrollbar = tk.Scrollbar(root, orient="vertical") 
ddlistbox = Drag_and_Drop_Listbox(root, yscrollcommand=scrollbar.set) 
scrollbar.grid(row=0, column=1, sticky='ns') 
scrollbar.config(command=ddlistbox.yview) 

def get_sqlite_report_fields(): 
    conn = sqlite3.connect('db.sqlite') 
    conn.row_factory = lambda cursor, row: row[0] 
    cursor = conn.cursor() 
    fetch = cursor.execute("SELECT fruit FROM columns ORDER BY 'ordering';").fetchall() 
    conn.close() 
    return fetch 

for fruit in get_sqlite_report_fields(): 
    ddlistbox.insert(0, fruit) 
ddlistbox.config(width=30) 
ddlistbox.bind('<Double-Button-1>' , func=update_ordering) 
ddlistbox.grid(row=0, column=0) 

button = tk.Button(root, text='Check', command=update_ordering) 
button.grid(row=1, column=0) 

root.mainloop() 

Answer 1

高度懷疑任何人會回答我的問題，所以我張貼我的解決方案。它使用拖放列表框來允許用戶在列表框中排列項目，並在下次將其項目排序保存到數據庫中。

import tkinter as tk 
import pandas as pd 
import sqlite3 
root = tk.Tk() 

class Drag_and_Drop_Listbox(tk.Listbox): 
    """ A tk listbox with drag'n'drop reordering of entries. """ 
    def __init__(self, master, **kw): 
    kw['selectmode'] = tk.EXTENDED 
    tk.Listbox.__init__(self, master, kw) 
    self.bind('<Button-1>', self.setCurrent) 
    self.bind('<B1-Motion>', self.shiftSelection) 
    self.curIndex = None 
    def setCurrent(self, event): 
    self.curIndex = self.nearest(event.y) 
    def shiftSelection(self, event): 
    i = self.nearest(event.y) 
    if i < self.curIndex: 
     x = self.get(i) 
     self.delete(i) 
     self.insert(i+1, x) 
     self.curIndex = i 
    elif i > self.curIndex: 
     x = self.get(i) 
     self.delete(i) 
     self.insert(i-1, x) 
     self.curIndex = i 

def update_ordering(*args): 
    connect = sqlite3.connect('db.sqlite') 
    cursor = connect.cursor() 
    field_ordering = [(order,fruit) for order,fruit in enumerate(ddlistbox.get(0, 'end'))] 
    print(field_ordering) 
    for field in field_ordering: 
    cursor.execute("UPDATE columns SET 'ordering'="+str(field[0])+" WHERE fruit='"+field[1]+"';") 
    connect.commit() 
    connect.close() 
    print(ddlistbox.curselection()) 

scrollbar = tk.Scrollbar(root, orient="vertical") 
ddlistbox = Drag_and_Drop_Listbox(root, yscrollcommand=scrollbar.set, activestyle='none') 
scrollbar.grid(row=0, column=1, sticky='ns') 
scrollbar.config(command=ddlistbox.yview) 

conn = sqlite3.connect('db.sqlite') 
conn.row_factory = lambda cursor, row: row[0] 
cursor = conn.cursor() 
fetch = cursor.execute("SELECT fruit FROM columns ORDER BY ordering ASC").fetchall() 
for field in fetch: 
    ddlistbox.insert(tk.END, field) 
ddlistbox.config(width=30) 
ddlistbox.grid(row=0, column=0) 

button = tk.Button(root, text='Check', command=update_ordering) 
button.grid(row=1, column=0) 

root.mainloop()