Files
PyDBLink/mysql_db.py
2025-12-29 22:08:58 +08:00

114 lines
3.8 KiB
Python

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
MySQL 数据库操作模块
支持基本的增删改查操作
"""
import sys
try:
import pymysql
from pymysql.cursors import DictCursor
except ImportError as e:
print(f"错误: 无法导入 pymysql 库,请确保已安装: pip install pymysql")
print(f"详细错误: {e}")
sys.exit(1)
class MySQLDatabase:
"""MySQL 数据库连接和操作类"""
def __init__(self, host='localhost', port=3306, user='root', password='', database=None):
"""
初始化 MySQL 连接参数
:param host: 数据库主机地址
:param port: 数据库端口
:param user: 用户名
:param password: 密码
:param database: 数据库名(可选,不指定则只连接到服务器)
"""
self.host = host
self.port = port
self.user = user
self.password = password
self.database = database
self.connection = None
def connect(self):
"""建立数据库连接"""
try:
conn_params = {
'host': self.host,
'port': self.port,
'user': self.user,
'password': self.password,
'charset': 'utf8mb4',
'cursorclass': DictCursor
}
# 如果指定了数据库,则连接到该数据库
if self.database:
conn_params['database'] = self.database
self.connection = pymysql.connect(**conn_params)
msg = f"MySQL 连接成功" + (f" (数据库: {self.database})" if self.database else " (未选择数据库)")
return True, msg
except Exception as e:
return False, f"MySQL 连接失败: {str(e)}"
def execute(self, sql, params=None):
"""
执行 SQL 语句
:param sql: SQL 语句
:param params: 参数(可选)
:return: 执行结果
"""
if not self.connection:
return False, "未连接到数据库"
try:
with self.connection.cursor() as cursor:
cursor.execute(sql, params)
# 判断是查询还是修改操作
if sql.strip().upper().startswith(('SELECT', 'SHOW', 'DESC', 'DESCRIBE')):
result = cursor.fetchall()
return True, result
else:
self.connection.commit()
return True, f"影响行数: {cursor.rowcount}"
except Exception as e:
self.connection.rollback()
return False, f"执行失败: {str(e)}"
def list_databases(self):
"""列出所有数据库"""
if not self.connection:
return False, "未连接到数据库"
try:
with self.connection.cursor() as cursor:
cursor.execute("SHOW DATABASES")
result = cursor.fetchall()
databases = [db['Database'] for db in result]
return True, databases
except Exception as e:
return False, f"获取数据库列表失败: {str(e)}"
def use_database(self, database):
"""切换到指定数据库"""
if not self.connection:
return False, "未连接到数据库"
try:
self.connection.select_db(database)
self.database = database
return True, f"已切换到数据库: {database}"
except Exception as e:
return False, f"切换数据库失败: {str(e)}"
def close(self):
"""关闭数据库连接"""
if self.connection:
self.connection.close()
self.connection = None
return "MySQL 连接已关闭"
return "连接已经关闭"