使用 tkinter 按钮从 MySQL 获取数据会重复

Question

我有一个 python 脚本，它使用 tkinter 和一个按钮从 MySQL 获取数据，但每次我按下按钮时，数据都会像这样复制：

代码如下：

from tkinter import ttk
import tkinter as tk
import mysql.connector

def View():
    mydb = mysql.connector.connect(
    host="localhost",
    user="",
    password="",
    database=""
    )
    mycursor = mydb.cursor()
    mycursor.execute("SELECT * FROM patients")
    rows = mycursor.fetchall()
    for row in rows:
        print(row) 
        tree.insert("", tk.END, values=row)
    mydb.close()

# connect to the database
root = tk.Tk()
root.geometry("900x350")
tree = ttk.Treeview(root, column=("c1", "c2", "c3"), show='headings')
tree.column("#1", anchor=tk.CENTER)
tree.heading("#1", text="ID")
tree.column("#2", anchor=tk.CENTER)
tree.heading("#2", text="First Name")
tree.column("#3", anchor=tk.CENTER)
tree.heading("#3", text="Country")

tree.pack()
button1 = tk.Button(text="Display data", command=View)
button1.pack()
root.mainloop()

清除上次获取的数据后，如何使其成为print/get数据？

此致，

Answer 1

你可以做一个简单的检查，如果里面有item就删除所有item，如果没有就插入，比如：

def View():
    if len(tree.get_children()): # If there are items inside 
        tree.delete(*tree.get_children()) # Delete all the items
    else:
        # Paste the rest of code

你也可以定义一个标志，然后检查是否有数据插入，并进行相应的处理，如：

inserted = False # Initially False
def View():
    if inserted:
        tree.delete(*tree.get_children())
        inserted = False # Set it to not inserted 
    if not inserted: # Let this get triggered
        # Same code
        for row in rows:
            print(row) 
            tree.insert("", tk.END, values=row)
        mydb.close()
        inserted = True # Set it to true.

使用 tkinter 按钮从 MySQL 获取数据会重复

Getting data from MySQL using tkinter button gets duplicated

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