python操作MySQL数据库报错问题解决

编写好Python操作数据库的脚本后，运行报错如下：

报错1：“AttributeError: 'NoneType' object has no attribute 'encoding'”

解决办法：设置charset时要用utf8，不能用utf-8

    if link_type == 0:
                # 创建数据，返回字典
                self.conn = pymysql.connect(host=host_db, user=user_db, password=password_db, db=name_db, port=port_db,
                                            charset='utf8', cursorclass=pymysql.cursors.DictCursor)
            else:
                # 创建数据库，返回元祖
                self.conn = pymysql.connect(host=host_db, user=user_db, password=password_db, db=name_db, port=port_db,
                                            charset='utf8')

报错2：“AttributeError: 'OperationDbInterface' object has no attribute 'cur'”

错误原因：编写代码时，换行时没有对齐，导致调用cur时报错

贴上Python操作mysql数据库的源码：

# coding:utf8

'''
定义对mysql数据库操作的封装
1、包括基本的单条语句操作，如删除、修改、插入
2、独立地查询单条、多条数据
3、独立地添加多条数据
'''

import logging, os, pymysql
from public import config

class OperationDbInterface(object):
    # 定义初始化数据库连接
    def __init__(self, host_db='127.0.0.1', user_db='root', password_db='',
                 name_db='interface_test', port_db=3306, link_type=0):
        '''
        :param host_db: 数据库服务主机IP
        :param user_db: 数据库连接用户名
        :param password_db: 数据库密码
        :param name_db: 数据库名称
        :param port_db: 数据库端口号，整型数据
        :param link_type: 连接类型，用于设置输出数据是元祖还是字典，默认是字典，link_type=0
        :return:游标
        '''
        try:
            if link_type == 0:
                # 创建数据，返回字典
                self.conn = pymysql.connect(host=host_db, user=user_db, password=password_db, db=name_db, port=port_db,
                                            charset='utf8', cursorclass=pymysql.cursors.DictCursor)
            else:
                # 创建数据库，返回元祖
                self.conn = pymysql.connect(host=host_db, user=user_db, password=password_db, db=name_db, port=port_db,
                                            charset='utf8')
            self.cur = self.conn.cursor()
            print("输出：%s" % self.cur)
        except pymysql.Error as e:
            print("创建数据库连接失败|Mysql Error %d: %s" % (e.args[0], e.args[1]))
            logging.basicConfig(filename=config.src_path + '/log/syserror.log', level=logging.DEBUG,
                                format='%(asctime)s %(filename)s[line:%(lineno)d] %(levelname)s %(message)s')
            logger = logging.getLogger(__name__)
            logger.exception(e)

    # 定义单条数据操作，包含删除和更新操作
    def op_sql(self, condition):
        '''
        :param condition: sql语句，该通用方法可用来替代updateone,deleteone
        :return: 字典形式
        '''

        try:
            self.cur.execute(condition)  # 执行sql语句
            self.conn.commit()  # 提交游标数据
            result = {'code': '', 'message': '执行通用操作成功', 'data': []}
        except pymysql.Error as e:
            self.conn.rollback()  # 执行回滚操作
            result = {'code': '', 'message': '执行通用操作异常', 'data': []}
            print("数据库错误|op_sql %d:%s" % (e.args[0], e.args[1]))
            logging.basicConfig(filename=config.src_path + '/log/syserror.log', level=logging.DEBUG,
                                format='%(asctime)s %(filename)s[line:%(lineno)d] %(levelname)s %(message)s')
            logger = logging.getLogger(__name__)
            logger.exception(e)
        return result

    # 查询表中单条数据
    def select_one(self, condition):
        '''
        :param condition: 查询单条sql语句
        :return: 字典形式的单条查询语句
        '''

        try:
            rows_affect = self.cur.execute(condition)
            if rows_affect > 0:
                results = self.cur.fetchone()  # 获取一条数据
                result = {'code': '', 'message': '执行单条查询操作成功', 'data': results}
            else:
                result = {'code': '', 'message': '执行单条查询操作成功', 'data': []}
        except pymysql.Error as e:
            self.conn.rollback()  # 执行回滚操作
            result = {'code': '', 'message': '执行单条查询异常', 'data': []}
            print("数据库错误|select_one %d: %s" % (e.args[0], e.args[1]))
            logging.basicConfig(filename=config.src_path + '/log/syserror.log', level=logging.DEBUG,
                                format='%(asctime)s %(filename)s [line:%(lineno)d] %(levelname)s %(message)s')
            logger = logging.getLogger(__name__)
            logger.exception(e)
        return result

    # 查询表中多条数据
    def select_all(self, condition):
        '''
        :param condition: sql语句
        :return: 字典形式的批量查询结果
        '''

        try:
            rows_affect = self.cur.execute(condition)
            if rows_affect > 0:
                # 将鼠标光标放回到初始位置
                self.cur.scroll(0, mode='absolute')
                # 返回游标中所有结果
                results = self.cur.fetchall()
                result = {'code': '', 'message': '执行批量查询操作成功', 'data': results}
            else:
                result = {'code': '', 'message': '执行批量查询操作成功', 'data': []}
        except pymysql.Error as e:
            # 执行回滚操作
            self.conn.rollback()
            result = {'code': '', 'message': '执行批量查询异常', 'data': []}
            logging.basicConfig(filename=config.src_path + '/log/syserror.log', level=logging.DEBUG,
                                format='%(asctime)s %(filename)s [line:%(lineno)d] %(levelname)s %(message)s')
            logger = logging.getLogger(__name__)
            logger.exception(e)
        return result

    # 定义表中插入数据操作的方法
    def insert_data(self, condition, params):
        '''
        :param condition: 插入语句
        :param params: 插入数据，列表形式[(,,,),(,,,)]
        :return: 字典形式批量插入数据结果
        '''
        try:
            results = self.cur.executemany(condition, params)  # 返回插入数据的条数
            self.conn.commit()
            result = {'code': '', 'message': '执行批量插入数据成功', 'data': results}
        except pymysql.Error as e:
            self.conn.rollback()  # 执行回滚操作
            result = {'code': '', 'message': '执行批量插入数据异常', 'data': []}
            print("数据库错误|insert_data %d: %s" % (e.args[0], e.args[1]))
            logging.basicConfig(filename=config.src_path + '/log/syserror.log', level=logging.DEBUG,
                                format='%(asctime)s %(filename)s [line:%(lineno)d] %(levelname)s %(massage)s')
            logger = logging.getLogger(__name__)
            logger.exception(e)
        return result

    # 关闭数据库
    def __del__(self):
        if self.cur is not None:
            self.cur.close()  # 关闭游标
        if self.conn is not None:
            self.conn.close()  # 释放数据库资源

if __name__ == "__main__":
    test = OperationDbInterface()  # 实例化类
    result_select_all = test.select_all("select * from config_test")  # 查询所有数据
    result_select_one = test.select_one("select * from config_test where id=1")  # 查询单条数据
    result_oP_sql = test.op_sql("UPDATE config_test SET value_config='修改后的valuetest' WHERE id=1")  # 通用操作，修改数据库
    result__insert_sql = test.insert_data(
        "insert into config_test (key_config, value_config, description, status) values (%s, %s, %s, %s)",
        [('mytest1', 'mytestvalue1', '我插入的测试数据1', 1), ('mytest2', 'mytestvalue2', '我插入的测试数据2', 0)])
    print(result_select_all['data'], result_select_all['message'])
    print(result_select_one['data'], result_select_one['message'])
    print(result_oP_sql['data'], result_oP_sql['message'])
    print(result__insert_sql['data'], result__insert_sql['message'])