Python Tkinter 循环在 INSERT SQLITE 之前验证输入

Question

我试图在将该信息插入 SQLITE 数据库之前验证条目。 我有一个带按钮的主 Tkinter 画布。 在这种情况下，该按钮会打开另一个窗口，用户可以在其中输入所需的字段。 我的想法是避免用户提交空字段。 我设法有一个消息框说出现了问题，但是一旦我按“确定”，代码就会继续并关闭输入窗口。 步骤 1 - 打开输入窗口：

def open_add_ship_window():
    global ship_window
    ship_window = Tk()
    ship_window.title('Add Ship')
    ship_window.iconbitmap(
        'C:/Users/eduardo.js.ramos/Desktop/VSCode/img directory/ship_icon_1.ico')
    ship_window.geometry("400x200")
    global ship_name_ship_window
    global ship_imo_ship_window
    global ISM_ship_window
    global ISM_IMO_ship_window
    # Create Text Boxes
    ship_name_ship_window = Entry(ship_window, width=40)
    ship_name_ship_window.grid(row=0, column=1, pady=(10, 0))
    ship_imo_ship_window = Entry(ship_window, width=40)
    ship_imo_ship_window.grid(row=1, column=1)
    ISM_ship_window = Entry(ship_window, width=40)
    ISM_ship_window.grid(row=2, column=1)
    ISM_IMO_ship_window = Entry(ship_window, width=40)
    ISM_IMO_ship_window.grid(row=3, column=1)
    # Create Labels
    ship_name_ship_window_label = Label(
        ship_window, text="Vessel Name")
    ship_name_ship_window_label.grid(row=0, column=0, pady=(10, 0))
    ship_imo_ship_window_label = Label(
        ship_window, text="Vessel IMO")
    ship_imo_ship_window_label.grid(row=1, column=0)
    ISM_ship_window_label = Label(ship_window, text="ISM Company")
    ISM_ship_window_label.grid(row=2, column=0)
    ISM_IMO_ship_window_label = Label(
        ship_window, text="ISM IMO Number")
    ISM_IMO_ship_window_label.grid(row=3, column=0)
    # Create Save New Ship Button
    save_ship_btn = Button(
        ship_window, text="Add New Ship", command=add_ship)
    save_ship_btn.grid(row=4, column=0, columnspan=2,
                       pady=10, padx=10, ipadx=50)

步骤 2 - 将数据提交到 SQLITE 数据库：

def add_ship():
    # connect to database
    conn = sqlite3.connect('PSC.sdb')
    # create cursor
    c = conn.cursor()
    while True:
        if len(ship_name_ship_window.get()) != 0 \
                or len(ship_imo_ship_window.get()) != 0 \
                or len(ISM_ship_window.get()) != 0 \
                or len(ISM_IMO_ship_window.get()) != 0:
            c.execute("INSERT INTO ships VALUES(:name, :imoship, :ism, :ismimo , null, null)",
                      {
                          'name': ship_name_ship_window.get(),
                          'imoship': ship_imo_ship_window.get(),
                          'ism': ISM_ship_window.get(),
                          'ismimo': ISM_IMO_ship_window.get()
                      })
        else:
            messagebox.showwarning(title='Review Needed', message='Please complete all fieds.')
            continue
    conn.commit()
    conn.close()
    ship_window.destroy()

大家有什么建议吗？

Answer 1

• 您应该将add_ship()的最后三行移动到if块中
• 在if语句中更改or and
• 删除while循环

下面是修改后的add_ship() ：

def add_ship():
    # get the information
    ship_name = ship_name_ship_window.get().strip()
    ship_imo = ship_imo_ship_window.get().strip()
    ism_ship = ISM_ship_window.get().strip()
    ism_imo = ISM_IMO_ship_window.get().strip()
    # if all is input
    if ship_name and ship_imo and ism_ship and ism_imo:
        # connect to database
        conn = sqlite3.connect('PSC.sdb')
        # create cursor
        c = conn.cursor()
        c.execute("INSERT INTO ships VALUES (:name, :imoship, :ism, :ismimo, NULL, NULL)",
                  {
                      'name': ship_name,
                      'imoship': ship_imo,
                      'ism': ism_ship,
                      'ismimo': ism_imo
                  })
        conn.commit()
        conn.close()
        ship_window.destroy()
    else:
        messagebox.showwarning(title='Review Needed', message='Please complete all fieds.')

Answer 2

消息框关闭后，主循环结束，因此您可能必须将上述代码放入循环中，以便一旦消息框显示错误，循环就不会结束。

一种潜在的方式可能是：

While True :
"""Input tags here"""
if len(ship_name_ship_window.get()) != 0 \
                or len(ship_imo_ship_window.get()) != 0 \
                or len(ISM_ship_window.get()) != 0 \
                or len(ISM_IMO_ship_window.get()) != 0:
            c.execute("INSERT INTO ships VALUES(:name, :imoship, :ism, :ismimo , null, null)",
                      {
                          'name': ship_name_ship_window.get(),
                          'imoship': ship_imo_ship_window.get(),
                          'ism': ISM_ship_window.get(),
                          'ismimo': ISM_IMO_ship_window.get()
                      })
            break
else:
     messagebox.showwarning(title='Review Needed', message='Please complete all fieds.')
     continue