• python--同一mysql数据库下批量迁移数据


    最近接手些mysql数据库维护,发现mysql在批量操作方面就是个渣渣啊,比起MS SQL SERVER简直就是“不可同日而语”。

    咨询了下MySQL的高手,对于数据迁移这种问题,一种处理方式就是直接“一步到位” ,一次性将所有数据查询插入到另外一个表,然后再删除原表数据;另外一种处理方式就是使用pt--archiver工具来归档。

    然并卵,“一步到位”法太刺激,pt--archiver工具用不顺手,由于目前大部分的表都以自增id为主键,以此为此为前提自己写个小脚本,厚脸拿出来供各位参考:

    # coding: utf-8
    import MySQLdb
    import time
    
    # common config
    EXEC_DETAIL_FILE = 'exec_detail.txt'
    DATETIME_FORMAT = '%Y-%m-%d %X'
    Default_MySQL_Host = '192.168.166.169'
    Default_MySQL_Port = 3358
    Default_MySQL_User = "mysql_admin"
    Default_MySQL_Password = 'mysql@Admin@Pwd'
    Default_MySQL_Charset = "utf8"
    Default_MySQL_Connect_TimeOut = 120
    
    # Transfer Config
    Transfer_Database_Name = "db001"
    Transfer_Source_Table_Name = "tb2001"
    Transfer_Target_Table_Name = "tb2001_his"
    Transfer_Condition = "dt <'2016-10-01'"
    Transfer_Rows_Per_Batch = 10000
    Sleep_Second_Per_Batch = 0.5
    
    
    def get_time_string(dt_time):
        """
        获取指定格式的时间字符串
        :param dt_time: 要转换成字符串的时间
        :return: 返回指定格式的字符串
        """
        global DATETIME_FORMAT
        return time.strftime(DATETIME_FORMAT, dt_time)
    
    
    def get_time_string(dt_time):
        return time.strftime("%Y-%m-%d %X", dt_time)
    
    
    def highlight(s):
        return "%s[30;2m%s%s[1m" % (chr(27), s, chr(27))
    
    
    def print_warning_message(message):
        """
        以红色字体显示消息内容
        :param message: 消息内容
        :return: 无返回值
        """
        message = str(message)
        print(highlight('') + "%s[31;1m%s%s[0m" % (chr(27), message, chr(27)))
    
    
    def print_info_message(message):
        """
        以绿色字体输出提醒性的消息
        :param message: 消息内容
        :return: 无返回值
        """
        message = str(message)
        print(highlight('') + "%s[32;2m%s%s[0m" % (chr(27), message, chr(27)))
    
    
    def write_file(file_path, message):
        """
        将传入的message追加写入到file_path指定的文件中
        请先创建文件所在的目录
        :param file_path: 要写入的文件路径
        :param message: 要写入的信息
        :return:
        """
        file_handle = open(file_path, 'a')
        file_handle.writelines(message)
        # 追加一个换行以方便浏览
        file_handle.writelines(chr(13))
        file_handle.close()
    
    
    def get_mysql_connection():
        """
        根据默认配置返回数据库连接
        :return: 数据库连接
        """
        conn = MySQLdb.connect(
                host=Default_MySQL_Host,
                port=Default_MySQL_Port,
                user=Default_MySQL_User,
                passwd=Default_MySQL_Password,
                connect_timeout=Default_MySQL_Connect_TimeOut,
                charset=Default_MySQL_Charset,
                db=Transfer_Database_Name
        )
        return conn
    
    
    def mysql_exec(sql_script, sql_param=None):
        """
        执行传入的脚本,返回影响行数
        :param sql_script:
        :param sql_param:
        :return: 脚本最后一条语句执行影响行数
        """
        try:
            conn = get_mysql_connection()
            print_info_message("在服务器{0}上执行脚本:{1}".format(
                    conn.get_host_info(), sql_script))
            cursor = conn.cursor()
            if sql_param is not None:
                cursor.execute(sql_script, sql_param)
            else:
                cursor.execute(sql_script)
            affect_rows = cursor.rowcount
            conn.commit()
            cursor.close()
            conn.close()
            return affect_rows
        except Exception as ex:
            cursor.close()
            conn.rollback()
            raise Exception(str(ex))
    
    
    def mysql_exec_many(sql_script_list):
        """
        执行传入的脚本,返回影响行数
        :param sql_script_list: 要执行的脚本List,List中每个元素为sql_script, sql_param对
        :return: 返回执行每个脚本影响的行数列表
        """
        try:
            conn = get_mysql_connection()
            exec_result_list = []
            for sql_script, sql_param in sql_script_list:
                print_info_message("在服务器{0}上执行脚本:{1}".format(
                        conn.get_host_info(), sql_script))
                cursor = conn.cursor()
                if sql_param is not None:
                    cursor.execute(sql_script, sql_param)
                else:
                    cursor.execute(sql_script)
                affect_rows = cursor.rowcount
                exec_result_list.append("影响行数:{0}".format(affect_rows))
            conn.commit()
            cursor.close()
            conn.close()
            return exec_result_list
    
        except Exception as ex:
            cursor.close()
            conn.rollback()
            raise Exception(str(ex))
    
    
    def mysql_query(sql_script, sql_param=None):
        """
        执行传入的SQL脚本,并返回查询结果
        :param sql_script:
        :param sql_param:
        :return: 返回SQL查询结果
        """
        try:
            conn = get_mysql_connection()
            print_info_message("在服务器{0}上执行脚本:{1}".format(
                    conn.get_host_info(), sql_script))
            cursor = conn.cursor()
            if sql_param != '':
                cursor.execute(sql_script, sql_param)
            else:
                cursor.execute(sql_script)
            exec_result = cursor.fetchall()
            cursor.close()
            conn.close()
            return exec_result
        except Exception as ex:
            cursor.close()
            conn.close()
            raise Exception(str(ex))
    
    
    def get_column_info_list(table_name):
        sql_script = """
    DESC {0}
    """.format(table_name)
        column_info_list = []
        query_result = mysql_query(sql_script=sql_script, sql_param=None)
        for row in query_result:
            column_name = row[0]
            column_key = row[3]
            column_info = column_name, column_key
            column_info_list.append(column_info)
        return column_info_list
    
    
    def get_id_range():
        """
        按照传入的表获取要删除数据最大ID、最小ID、删除总行数
        :return: 返回要删除数据最大ID、最小ID、删除总行数
        """
        global Transfer_Condition
        global Transfer_Rows_Per_Batch
        sql_script = """
    SELECT
    MAX(ID) AS MAX_ID,
    MIN(ID) AS MIN_ID,
    COUNT(1) AS Total_Count
    FROM {0}
    WHERE {1};
    """.format(Transfer_Source_Table_Name, Transfer_Condition)
        query_result = mysql_query(sql_script=sql_script, sql_param=None)
        max_id, min_id, total_count = query_result[0]
        # 此处有一坑,可能出现total_count不为0 但是max_id 和min_id 为None的情况
        # 因此判断max_id和min_id 是否为NULL
        if (max_id is None) or (min_id is None):
            max_id, min_id, total_count = 0, 0, 0
        return max_id, min_id, total_count
    
    
    def check_env():
        try:
            source_columns_info_list = get_column_info_list(Transfer_Source_Table_Name)
            target_columns_info_list = get_column_info_list(Transfer_Target_Table_Name)
            if len(source_columns_info_list) != len(target_columns_info_list):
                print_info("源表和目标表的列数不对,不满足迁移条件")
                return False
            column_count = len(source_columns_info_list)
            id_flag = False
            for column_id in range(column_count):
                source_column_name, source_column_key = source_columns_info_list[column_id]
                target_column_name, target_column_key = target_columns_info_list[column_id]
                if source_column_name != target_column_name:
                    print_info("源表和目标表的列名不匹配,不满足迁移条件")
                    return False
                if source_column_name.lower() == 'id' 
                        and source_column_key.lower() == 'pri' 
                        and target_column_name.lower() == 'id' 
                        and target_column_key.lower() == 'pri':
                    id_flag = True
            if not id_flag:
                print_info("未找到为主键的id列,不满足迁移条件")
                return False
            return True
        except Exception as ex:
            print_info("执行出现异常,异常为{0}".format(ex.message))
            return False
    
    
    def main():
        flag = check_env()
        if not flag:
            return
        loop_trans_data()
    
    
    def trans_data(current_min_id, current_max_id):
        global Transfer_Source_Table_Name
        global Transfer_Target_Table_Name
        global Transfer_Condition
        global Transfer_Rows_Per_Batch
        print_info_message("*" * 70)
        copy_data_script = """
    INSERT INTO {0}
    SELECT * FROM {1}
    WHERE ID>={2}
    AND ID<{3}
    AND {4} ;
    """.format(Transfer_Target_Table_Name, Transfer_Source_Table_Name, current_min_id, current_max_id, Transfer_Condition)
        delete_data_script = """
    DELETE FROM {0}
    WHERE ID IN (
    SELECT ID
    FROM {1}
    WHERE ID>={2}
    AND ID<{3})
    AND ID>={4}
    AND ID<{5};
    """.format(Transfer_Source_Table_Name, Transfer_Target_Table_Name, current_min_id, current_max_id, current_min_id,
               current_max_id)
        sql_script_list = []
        tem_sql_script = copy_data_script, None
        sql_script_list.append(tem_sql_script)
        tem_sql_script = delete_data_script, None
        sql_script_list.append(tem_sql_script)
        exec_result_list = mysql_exec_many(sql_script_list)
        print_info_message("执行结果:")
        for item in exec_result_list:
            print_info_message(item)
    
    
    def loop_trans_data():
        max_id, min_id, total_count = get_id_range()
        if min_id == max_id:
            print_info_message("无数据需要结转")
            return
    
        current_min_id = min_id
        global Transfer_Rows_Per_Batch
        while current_min_id <= max_id:
            current_max_id = current_min_id + Transfer_Rows_Per_Batch
            trans_data(current_min_id, current_max_id)
            current_percent = (current_max_id - min_id) * 100.0 / (max_id - min_id)
            left_rows = max_id - current_max_id
            if left_rows < 0:
                left_rows = 0
            current_percent_str = "%.2f" % current_percent
            info = "当前复制进度{0}/{1},剩余{2},进度为{3}%".format(current_max_id,
                                                        max_id, left_rows,
                                                        current_percent_str)
            print_info_message(info)
            time.sleep(Sleep_Second_Per_Batch)
            current_min_id = current_max_id
        print_info_message("*" * 70)
        print_info_message("执行完成")
    
    
    if __name__ == '__main__':
        main()
    View Code

    按照各位场景的,需要修改数据库连接信息:

    还有需要迁移表的信息:

    生成测试数据的mysql脚本:

    CREATE TABLE `tb2001` (
      `id` int(11) NOT NULL AUTO_INCREMENT,
      `c1` varchar(200) DEFAULT NULL,
      `dt` datetime DEFAULT NULL,
      PRIMARY KEY (`id`)
    ) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;
    
    create table tb2001_his like tb2001;
    
    insert tb2001(c1,dt) select 'abc',date_add(localtime(),interval FLOOR(RAND() * 20000) hour) FROM mysql.user;
    insert tb2001(c1,dt) select 'abc',date_add(localtime(),interval FLOOR(RAND() * 20000) hour) FROM tb2001;
    insert tb2001(c1,dt) select 'abc',date_add(localtime(),interval FLOOR(RAND() * 20000) hour) FROM tb2001;
    insert tb2001(c1,dt) select 'abc',date_add(localtime(),interval FLOOR(RAND() * 20000) hour) FROM tb2001;
    insert tb2001(c1,dt) select 'abc',date_add(localtime(),interval FLOOR(RAND() * 20000) hour) FROM tb2001;
    insert tb2001(c1,dt) select 'abc',date_add(localtime(),interval FLOOR(RAND() * 20000) hour) FROM tb2001;
    insert tb2001(c1,dt) select 'abc',date_add(localtime(),interval FLOOR(RAND() * 20000) hour) FROM tb2001;
    insert tb2001(c1,dt) select 'abc',date_add(localtime(),interval FLOOR(RAND() * 20000) hour) FROM tb2001;
    insert tb2001(c1,dt) select 'abc',date_add(localtime(),interval FLOOR(RAND() * 20000) hour) FROM tb2001;
    insert tb2001(c1,dt) select 'abc',date_add(localtime(),interval FLOOR(RAND() * 20000) hour) FROM tb2001;
    insert tb2001(c1,dt) select 'abc',date_add(localtime(),interval FLOOR(RAND() * 20000) hour) FROM tb2001;
    insert tb2001(c1,dt) select 'abc',date_add(localtime(),interval FLOOR(RAND() * 20000) hour) FROM tb2001;
    insert tb2001(c1,dt) select 'abc',date_add(localtime(),interval FLOOR(RAND() * 20000) hour) FROM tb2001;
    insert tb2001(c1,dt) select 'abc',date_add(localtime(),interval FLOOR(RAND() * 20000) hour) FROM tb2001;
    insert tb2001(c1,dt) select 'abc',date_add(localtime(),interval FLOOR(RAND() * 20000) hour) FROM tb2001;
    insert tb2001(c1,dt) select 'abc',date_add(localtime(),interval FLOOR(RAND() * 20000) hour) FROM tb2001;
    View Code

    最终运行结果如下:

    显示简单粗暴,有兴趣的可以在此基础上修改!

    =================================================================

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  • 原文地址:https://www.cnblogs.com/TeyGao/p/5948934.html
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