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python--同一mysql数据库下批量迁移数据

2018-06-17 23:04:25来源：未知阅读 ()

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;