解决 PyMySQL 连接 TypeError 的正确姿势

import pymysql as mdb

db_host = 'some.server.co.uk'
db_user = 'my_username'
db_pass = 'my_password'
db_name = 'my_db_name'

# 错误示范：使用位置参数
db = mdb.connect(db_host, db_user, db_pass, db_name)

import pymysql

# 假设这些配置来自您的 dbconfig 模块或环境变量
db_host = 'localhost' # 或 'some.server.co.uk'
db_user = 'your_username'
db_pass = 'your_password'
db_name = 'your_database_name'
db_port = 3306 # 默认端口，如果非默认则需指定

try:
    # 正确示范：使用关键字参数
    connection = pymysql.connect(
        host=db_host,
        user=db_user,
        password=db_pass,
        database=db_name,
        port=db_port, # 可选，如果使用非标准端口
        charset='utf8mb4', # 推荐指定字符集
        cursorclass=pymysql.cursors.DictCursor # 可选，返回字典形式的结果
    )
    print("数据库连接成功！")

    # 执行一些数据库操作
    with connection.cursor() as cursor:
        # 示例：创建表
        sql_create_table = """
        CREATE TABLE IF NOT EXISTS example_table (
            id INT AUTO_INCREMENT PRIMARY KEY,
            name VARCHAR(255) NOT NULL,
            age INT
        )
        """
        cursor.execute(sql_create_table)
        print("表 'example_table' 检查或创建完成。")

        # 示例：插入数据
        sql_insert = "INSERT INTO example_table (name, age) VALUES (%s, %s)"
        cursor.execute(sql_insert, ('Alice', 30))
        cursor.execute(sql_insert, ('Bob', 24))
        connection.commit() # 提交事务
        print("数据插入成功。")

        # 示例：查询数据
        sql_select = "SELECT id, name, age FROM example_table WHERE age > %s"
        cursor.execute(sql_select, (25,))
        result = cursor.fetchall()
        print("\n查询结果 (年龄大于25):")
        for row in result:
            print(row)

except pymysql.Error as e:
    print(f"数据库连接或操作失败: {e}")
finally:
    if 'connection' in locals() and connection.open:
        connection.close()
        print("数据库连接已关闭。")