解决Python Tkinter CRUD应用中的MySQL连接不可用错误

File "C:\Users\mclov\pythonProject1\lira.py", line 14, in inserir
    cursor = conexao.cursor()
File "C:\Users\mclov\abadabado\lib\site-packages\mysql\connector\connection_cext.py", line 706, in cursor
    raise OperationalError("MySQL Connection not available.")
mysql.connector.errors.OperationalError: MySQL Connection not available.

import mysql.connector
from mysql.connector import Error

try:
    connection = mysql.connector.connect(host='localhost',
                                         database='your_database_name',
                                         user='your_username',
                                         password='your_password')
    if connection.is_connected():
        db_Info = connection.get_server_info()
        print("成功连接到MySQL数据库版本:", db_Info)
        cursor = connection.cursor()
        cursor.execute("SELECT DATABASE();")
        record = cursor.fetchone()
        print("您已连接到数据库:", record)

except Error as e:
    print("连接MySQL数据库时发生错误:", e)

finally:
    if 'connection' in locals() and connection.is_connected():
        cursor.close()
        connection.close()
        print("MySQL连接已关闭")

import mysql.connector
from mysql.connector import Error

# 假设这些是全局或从配置中读取的数据库连接参数
DB_CONFIG = {
    'host': 'localhost',
    'database': 'your_database_name',
    'user': 'your_username',
    'password': 'your_password'
}

def inserir(data_list):
    """
    将数据插入到数据库中。
    data_list 预期包含 [tempo, evento, debito, credito]
    """
    connection = None
    cursor = None
    try:
        # 1. 建立数据库连接
        connection = mysql.connector.connect(**DB_CONFIG)

        if connection.is_connected():
            cursor = connection.cursor()

            # 2. 准备SQL插入语句
            sql_insert_query = """
            INSERT INTO your_table_name (tempo, evento, debito, credito)
            VALUES (%s, %s, %s, %s)
            """
            # 确保 data_list 中的元素类型与数据库字段匹配
            # 例如，如果 debito 和 credito 是数值类型，需要转换为 float 或 int
            processed_data = (
                data_list[0],
                data_list[1],
                float(data_list[2]) if data_list[2] else 0.0, # 示例：处理空字符串或转换为浮点数
                float(data_list[3]) if data_list[3] else 0.0
            )

            # 3. 执行SQL语句
            cursor.execute(sql_insert_query, processed_data)

            # 4. 提交事务
            connection.commit()
            print("数据插入成功！")
            return True
        else:
            print("未能建立数据库连接。")
            return False

    except Error as e:
        print(f"插入数据时发生错误: {e}")
        if connection:
            connection.rollback() # 发生错误时回滚事务
        return False
    finally:
        # 5. 关闭游标和连接，确保资源释放
        if cursor:
            cursor.close()
        if connection and connection.is_connected():
            connection.close()
            print("MySQL连接已关闭。")

from tkinter import messagebox
# 假设 inserir 函数已定义并可导入
# from .lira import inserir # 如果 inserir 在 lira.py 中

def insertdata():
    tempo = entry_tempo.get()
    evento = entry_descrição.get()
    debito = entry_entrada.get()
    credito = entry_saida.get()

    # 1. 输入验证
    if not (tempo and evento and debito and credito): # 简化非空判断
        messagebox.showerror("输入错误", "所有字段都不能为空！") # 增加标题
        return # 验证失败，直接返回，不继续执行

    lista = [tempo, evento, debito, credito]

    # 2. 调用 inserir 函数并处理其返回值
    if inserir(lista): # 假设 inserir 返回 True 表示成功，False 表示失败
        messagebox.showinfo("操作成功", "所有数据已成功注册。")
        # 清空输入字段
        entry_tempo.delete(0, "end")
        entry_descrição.delete(0, "end")
        entry_entrada.delete(0, "end")
        entry_saida.delete(0, "end")
    else:
        messagebox.showerror("操作失败", "数据注册失败，请检查日志或数据库连接。")

    # 3. 刷新UI（假设 frame_tabela 和 showitself() 存在）
    for widget in frame_tabela.winfo_children():
        widget.destroy()
    showitself()