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[SQL Server] 基于Python的SQL Server数据库实现对象同步轻量级

数据库 数据库 发布于:2021-06-25 12:08 | 阅读数:292 | 评论:0

  缘由
  日常工作中经常遇到类似的问题:把某个服务器上的某些指定的表同步到另外一台服务器。

  类似需求用SSIS或者其他ETL工作很容易实现,比如用SSIS的话,就会会存在相当一部分反复的手工操作。

  建源的数据库信息,目标的数据库信息,如果是多个表,需要一个一个地拉source和target,然后一个一个地mapping,然后运行实现数据同步。

  然后很可能,这个workflow使用也就这么一次,就寿终正寝了,却一样要浪费时间去做这个ETL。
  快速数据同步实现
  于是在想,可不可能快速实现类似需求,尽最大程度减少重复的手工操作?类似基于命令行的方式,简单快捷,不需要太多的手动操作。

  于是就有了本文,基于Python(目的是顺便熟悉一下Python的语法),快速实现SQL Server的数据库之间的数据同步操作,后面又稍微扩展了一下,可以实现不同服务器的数据库之间的表结构,表对应的数据,存储过程,函数,用户自定义类型表(user define table type)的同步

  目前支持在两个SQL Server数据源之间:每次同步一张或者多张表/存储过程,也可以同步整个数据库的所有表/存储过程(以及表/存储过程依赖的其他数据库对象)。

  支持sqlserver2012以上版本
  需要考虑到一些基本的校验问题:在源服务器上,需要同步的对象是否存在,或者输入的对象是否存在于源服务器的数据库里。
  在目标服务器上,对于表的同步:

  1,表的存在依赖于schema,需要考虑到表的schema是否存在,如果不存在先在target库上创建表对应的schema

  2,target表中是否有数据?如果有数据,是否以覆盖的方式执行

  对于存储过程的同步:

  1,类似于表,需要考虑存储过程的schema是否存在,如果不存在先在target库上创建表对应的schema
2,类似于表,arget数据库中是否已经存在对应的存储过程,是否以覆盖的方式执行
3,存储过程可能依赖于b表,某些函数,用户自定义表变量等等,同步存储过程的时候需要先同步依赖的对象,这一点比较复杂,实现过程中遇到在很多很多的坑

  可能存在对象A依赖于对象B,对象B依赖于对象C……,这里有点递归的意思

  这一点导致了重构大量的代码,一开始都是直来直去的同步,无法实现这个逻辑,切实体会到代码的“单一职责”原则
  参数说明

  参数说明如下,大的包括四类:

  1,源服务器信息 (服务器地址,实例名,数据库名称,用户名,密码),没有用户名密码的情况下,使用windows身份认证模式

  2,目标服务器信息(服务器地址,实例名,数据库名称,用户名,密码),没有用户名密码的情况下,使用windows身份认证模式

  3,同步的对象类型以及对象

  4,同步的对象在目标服务器上存在的情况下,是否强制覆盖
DSC0000.png

  其实在同步数据的时候,也可以把需要同步的行数提取出来做参数,比较简单,这里暂时没有做。

  比如需要快速搭建一个测试环境,需要同步所有的表结构和每个表的一部分数据即可。
  表以及数据同步
  表同步的原理是,创建目标表,遍历源数据的表,生成insert into values(***),(***),(***)格式的sql,然后插入目标数据库,这里大概步骤如下:

  1,表依赖于schema,所以同步表之前先同步schema

  2,强制覆盖的情况下,会drop掉目标表(如果存在的话),防止目标表与源表结构不一致,非强制覆盖的情况下,如果字段不一致,则抛出异常

  3,同步表结构,包括字段,索引,约束等等,但是无法支持外键,刻意去掉了外键,想想为什么?因吹斯汀。

  4,需要筛选出来非计算列字段,insert语句只能是非计算列字段(又导致重构了部分代码)

  5,转义处理,在拼凑SQL的时候,需要进行转义处理,否则会导致SQL语句错误,目前处理了字符串中的'字符,二进制字段,时间字段的转义处理(最容易发生问题的地方)

  6,鉴于insert into values(***),(***),(***)语法上允许的最大值是1000,因此每生成1000条数据,就同步一次

  7,自增列的identity_insert 标识打开与关闭处理
  使用如下参数,同步源数据库的三张表到目标数据库,因为这里是在本机命名实例下测试,因此实例名和端口号输入
  执行同步的效果
DSC0001.gif

  说明:

  1,如果输入obj_type="tab" 且-obj=为None的情况下,会同步源数据库中的所有表。
2,这个效率取决于机器性能和网络传输,本机测试的话,每秒中可以提交3到4次,也就是每秒钟可以提交3000~4000行左右的数据。
  已知的问题:

  1,当表的索引为filter index的时候,无法生成包含where条件的索引创建语句,那个看起来蛋疼的表结构导出语句,暂时没时间改它。
2,暂时不支持其他少用的类型字段,比如地理空间字段什么的。
  存储过程对象的同步
  存储过程同步的原理是,在源数据库上生成创建存储过程的语句,然后写入目标库,这里大概步骤如下:
1,存储过程依赖于schema,所以同步存储过程之前先同步schema(同表)
2,同步的过程会检查依赖对象,如果依赖其他对象,暂停当前对象同步,先同步依赖对象
3,重复第二步骤,直至完成
4,对于存储过程的同步,如果是强制覆盖的话,强制覆盖仅仅对存储过程自己生效(删除&重建),对依赖对象并不生效,如果依赖对象不存在,就创建,否则不做任何事情
  使用如下参数,同步源数据库的两个存储过程到目标数据库,因为这里是在本机命名实例下测试,因此实例名和端口号输入
  说明:测试要同步的存储过程之一为[dbo].[sp_test01],它依赖于其他两个对象:dbo.table01和dbo.fn_test01()
create proc [dbo].[sp_test01]
as
begin
 set no count on;
 delete from dbo.table01 where id = 1000
 select dbo.fn_test01()
end
  而dbo.fn_test01()的如下,依赖于另外一个对象:dbo.table02
create function [dbo].[fn_test01]
(
)
RETURNS int
AS
BEGIN 
 declare @count int = 0
 select @count = count(1) from dbo.table02
 return @count
END
  因此,这个测试的[dbo].[sp_test01]就依赖于其他对象,如果其依赖的对象不存在,同步的时候,仅仅同步这个存储过程本身,是没有意义的

  同步某一个对象的依赖对象,使用如下SQL查出来对象依赖信息,因此这里就层层深入,同步依赖对象。
这里就类似于同步A的时候,A依赖于B和C,然后停止同步A,先同步B和C,同步B或者C的时候,可能又依赖于其他对象,然后继续先同步其依赖对象。
DSC0002.png

  效果如下
DSC0003.gif

  如果输入obj_type="sp" 且-obj=为None的情况下,会同步源数据库中的所有存储过程以及其依赖对象
  已知的问题:

  1,加密的存储过程或者函数是无法实现同步的,因为无法生成创建对象的脚本
1,table type的同步也是一个蛋疼的过程,目前支持,但是支持的并不好,原因是创建table type之前,先删除依赖于table type的对象,否则无法删除与创建。
  特别说明
  依赖对象的解决,还是比较蛋疼的

  如果在默认schema为dbo的对象,在存储过程或者函数中没有写schema(参考如下修改后的sp,不写相关表的schema dbo,dbo.test01==>test01),
使用 sys.dm_sql_referenced_entities这个系统函数是无法找到其依赖的对象的,奇葩的是可以找到schema的类型,却没有返回对象本身。

  这一点导致在代码中层层深入,进行了长时间的debug,完全没有想到这个函数是这个鸟样子,因为这里找到依赖对象的类型,却找不到对象本身,次奥!!!
另外一种情况就是动态SQL了,无法使用 sys.dm_sql_referenced_entities这个系统函数找到其依赖的对象。
DSC0004.png

  其他对象的同步
  支持其他数据库对象的同步,比如function,table type等,因为可以在同步其他存储过程对象的时候附带的同步function,table type,这个与表或者存储过程类似,不做过多说明。 
  已知问题:
  1,201906122030:经测试,目前暂时不支持Sequence对象的同步。
  需要改进的地方
  1,代码结构优化,更加清晰和条例的结构(一开始用最直接简单粗暴的方式快速实现,后面重构了很多代码,现在自己看起来还有很多不舒服的痕迹)
2,数据同步的效率问题,对于多表的导入导出操作,依赖于单线程,多个大表导出串行的话,可能存在效率上的瓶颈,如何根据表的数据量,尽可能平均地分配多多个线程中,提升效率
3,更加友好清晰的异常提示以及日志记录,生成导出日志信息。
4,异构数据同步,MySQL《==》SQL Server《==》Oracle《==》PGSQL
  代码端午节写好了,这几天抽空进行了一些测试以及bug fix,应该还潜在不少未知的bug,工作量比想象中的大的多了去了。
# -*- coding: utf-8 -*-
# !/usr/bin/env python3

__author__ = 'MSSQL123'
__date__ = '2019-06-07 09:36'

import os
import sys
import time
import datetime
import pymssql
from decimal import Decimal

usage = '''
   -----parameter explain-----

   source database parameter
   -s_h    : soure database host           ----- must require parameter
   -s_i    : soure database instace name         ----- default instance name MSSQL
   -s_d    : soure database name           ----- must require parameter
   -s_u    : soure database login           ----- default windows identifier
   -s_p    : soure database login password        ----- must require when s_u is not null
   -s_P    : soure database instance port         ----- default port 1433

   target database parameter
   -t_h    : target database host           ----- must require parameter
   -t_i    : target database instace name         ----- default instance name MSSQL
   -t_d    : target database name           ----- must require parameter
   -t_u    : target database login          ----- default windows identifier
   -t_p    : target database login password        ----- must require when s_u is not null
   -t_P    : target database instance port        ----- default port 1433

   sync object parameter
   -obj_type   : table or sp or function or other databse object     ----- tab or sp or fn or tp
   -obj    : table|sp|function|type name         ----- whick table or sp sync

   overwirte parameter
   -f     : force overwirte target database object        ----- F or N 


   --help: help document
   Example:
   python DataTransfer.py -s_h=127.0.0.1 -s_P=1433 -s_i="MSSQL" -s_d="DB01" -obj_type="tab" -obj="dbo.t1,dbo.t2" -t_h=127.0.0.1 -t_P=1433 -t_i="MSSQL" -t_d="DB02" -f="Y"      
   python DataTransfer.py -s_h=127.0.0.1 -s_P=1433 -s_i="MSSQL" -s_d="DB01" -obj_type="sp" -obj="dbo.sp1,dbo.sp2" -t_h=127.0.0.1 -t_P=1433 -t_i="MSSQL" -t_d="DB02" -f="Y"
   '''


class SyncDatabaseObject(object):
  # source databse
  s_h = None
  s_i = None
  s_P = None
  s_u = None
  s_p = None
  s_d = None

  # obj type
  s_obj_type = None
  # sync objects
  s_obj = None

  # target database
  t_h = None
  t_i = None
  t_P = None
  t_u = None
  t_p = None
  t_d = None

  f = None

  file_path = None

  def __init__(self, *args, **kwargs):
  for k, v in kwargs.items():
    setattr(self, k, v)

  # connect to sqlserver
  def get_connect(self, _h, _i, _P, _u, _p, _d):
  cursor = False
  try:
    if (_u) and (_p):
    conn = pymssql.connect(host=_h,
          server=_i,
          port=_P,
          user=_u,
          password=_p,
          database=_d)
    else:
    conn = pymssql.connect(host=_h,
          server=_i,
          port=_P,
          database=_d)
    if (conn):
    return conn
  except:
    raise
  return conn

  # check connection
  def validated_connect(self, _h, _i, _P, _u, _p, _d):
  if not (self.get_connect(_h, _i, _P, _u, _p, _d)):
    print("connect to " + str(_h) + " failed,please check you parameter")
    exit(0)

  '''
  this is supposed to be a valid object name just like xxx_name,or dbo.xxx_name,or [schema].xxx_name or schema.[xxx_name]
  then transfer this kind of valid object name to format object name like [dbo].[xxx_name](give a default dbo schema name when no schema name)
  other format object name consider as unvalid,will be rasie error in process
  format object name
  1,xxx_name     ======> [dbo].[xxx_name]
  2,dbo.xxx_name   ======> [dbo].[xxx_name]
  3,[schema].xxx_name   ======> [dbo].[xxx_name]
  3,schema.xxx_name  ======> [schema].[xxx_name]
  4,[schema].[xxx_name]  ======> [schema].[xxx_name]
  5,[schema].[xxx_name  ======> rasie error format message
  '''

  @staticmethod
  def format_object_name(name):
  format_name = ""
  if ("." in name):
    schema_name = name[0:name.find(".")]
    object_name = name[name.find(".") + 1:]
    if not ("[" in schema_name):
    schema_name = "[" + schema_name + "]"
    if not ("[" in object_name):
    object_name = "[" + object_name + "]"
    format_name = schema_name + "." + object_name
  else:
    if ("[" in name):
    format_name = "[dbo]." + name
    else:
    format_name = "[dbo]." + "[" + name + "]"
  return format_name

  '''
  check user input object is a valid object
  '''

  def exits_object(self, conn, name):
  conn = conn
  cursor_source = conn.cursor()
  # get object by name from source db
  sql_script = r'''select top 1 1 from
        (
          select concat(QUOTENAME(schema_name(schema_id)),'.',QUOTENAME(name)) as obj_name from sys.objects 
          union all
          select concat(QUOTENAME(schema_name(schema_id)),'.',QUOTENAME(name)) as obj_name from sys.types 
        )t where obj_name = '{0}'
         '''.format(self.format_object_name(name))
  cursor_source.execute(sql_script)
  result = cursor_source.fetchall()
  if not result:
    return 0
  else:
    return 1
  conn.cursor.close()
  conn.close()

  # table variable sync
  def sync_table_variable(self, tab_name, is_reference):
  conn_source = self.get_connect(self.s_h, self.s_i, self.s_P, self.s_u, self.s_p, self.s_d)
  conn_target = self.get_connect(self.t_h, self.t_i, self.t_P, self.t_u, self.t_p, self.t_d)
  cursor_source = conn_source.cursor()
  cursor_target = conn_target.cursor()

  if (self.exits_object(conn_source, self.format_object_name(tab_name))) > 0:
    pass
  else:
    print("----------------------- warning message -----------------------")
    print("--------warning: object " + tab_name + " not existing in source database ------------")
    print("----------------------- warning message -----------------------")
    print()
    return

  exists_in_target = 0
  sql_script = r'''select top 1 1
         from sys.table_types tp
         where is_user_defined = 1 
         and concat(QUOTENAME(schema_name(tp.schema_id)),'.',QUOTENAME(tp.name)) = '{0}' ''' \
    .format((self.format_object_name(tab_name)))
  # if the table schema exists in target server,skip
  cursor_target.execute(sql_script)
  exists_in_target = cursor_target.fetchone()

  # weather exists in target server database
  if (self.f == "Y"):
    if (is_reference != "Y"):
    # skiped,table type can not drop when used by sp
    sql_script = r'''
           if OBJECT_ID('{0}') is not null
             drop type {0}
           '''.format(self.format_object_name(tab_name))
    cursor_target.execute(sql_script)
    conn_target.commit()
  else:
    if exists_in_target:
    print("----------------------- warning message -----------------------")
    print("the target table type " + tab_name + " exists ,skiped sync table type from source")
    print("----------------------- warning message -----------------------")
    print()
    return

  sql_script = r'''   
          DECLARE @SQL NVARCHAR(MAX) = ''

          SELECT @SQL =
          'CREATE TYPE ' + '{0}' + 'AS TABLE' + CHAR(13) + '(' + CHAR(13) +
          STUFF((
              SELECT CHAR(13) + '  , [' + c.name + '] ' +
              CASE WHEN c.is_computed = 1
                THEN 'AS ' + OBJECT_DEFINITION(c.[object_id], c.column_id)
                ELSE
                CASE WHEN c.system_type_id != c.user_type_id
                  THEN '[' + SCHEMA_NAME(tp.[schema_id]) + '].[' + tp.name + ']'
                  ELSE '[' + UPPER(y.name) + ']'
                END +
                CASE
                  WHEN y.name IN ('varchar', 'char', 'varbinary', 'binary')
                  THEN '(' + CASE WHEN c.max_length = -1


                      THEN 'MAX'
                      ELSE CAST(c.max_length AS VARCHAR(5))
                      END + ')'
                  WHEN y.name IN ('nvarchar', 'nchar')
                  THEN '(' + CASE WHEN c.max_length = -1
                      THEN 'MAX'
                      ELSE CAST(c.max_length / 2 AS VARCHAR(5))
                      END + ')'
                  WHEN y.name IN ('datetime2', 'time2', 'datetimeoffset')
                  THEN '(' + CAST(c.scale AS VARCHAR(5)) + ')'
                  WHEN y.name = 'decimal'
                  THEN '(' + CAST(c.[precision] AS VARCHAR(5)) + ',' + CAST(c.scale AS VARCHAR(5)) + ')'
                  ELSE ''
                END +
                CASE WHEN c.collation_name IS NOT NULL AND c.system_type_id = c.user_type_id
                  THEN ' COLLATE ' + c.collation_name
                  ELSE ''
                END +
                CASE WHEN c.is_nullable = 1
                  THEN ' NULL'
                  ELSE ' NOT NULL'
                END +
                CASE WHEN c.default_object_id != 0
                  THEN ' CONSTRAINT [' + OBJECT_NAME(c.default_object_id) + ']' +
                    ' DEFAULT ' + OBJECT_DEFINITION(c.default_object_id)
                  ELSE ''
                END
              END
              From sys.table_types tp
              Inner join sys.columns c on c.object_id = tp.type_table_object_id
              Inner join sys.types y ON y.system_type_id = c.system_type_id 
              WHERE tp.is_user_defined = 1 and y.name<>'sysname'
              and concat(QUOTENAME(schema_name(tp.schema_id)),'.',QUOTENAME(tp.name)) = '{0}'
              ORDER BY c.column_id

          FOR XML PATH(''), TYPE).value('.', 'NVARCHAR(MAX)'), 1, 7, '   ')
          + ');'

          select @SQL as script
        '''.format(self.format_object_name(self.format_object_name((tab_name))))
  cursor_target = conn_target.cursor()
  cursor_source.execute(sql_script)
  row = cursor_source.fetchone()
  try:
    if not exists_in_target:
    # execute the script on target server
    cursor_target.execute(str(row[0])) # drop current stored_procudre if exists
    conn_target.commit()
    print("*************table type " + self.format_object_name(tab_name) + " synced *********************")
    print() # give a blank row when finish
  except:
    print("----------------------- error message -----------------------")
    print("-----------table type " + self.format_object_name(tab_name) + " synced error ---------------")
    print("----------------------- error message -----------------------")
    print()
    # raise

  cursor_source.close()
  conn_source.close()
  cursor_target.close()
  conn_target.close()

  # schema sync
  def sync_schema(self):
  conn_source = self.get_connect(self.s_h, self.s_i, self.s_P, self.s_u, self.s_p, self.s_d)
  conn_target = self.get_connect(self.t_h, self.t_i, self.t_P, self.t_u, self.t_p, self.t_d)
  cursor_source = conn_source.cursor()
  cursor_target = conn_target.cursor()
  arr_schema = []
  # get all table in database when not define table name
  schema_result = cursor_source.execute(r'''
             select name from sys.schemas where schema_id>4 and schema_id<16384
            ''')
  for row in cursor_source.fetchall():
    cursor_target.execute(r''' if not exists(select * from sys.schemas where name = '{0}')
             begin
               exec('create schema [{0}]')
             end
             '''.format(str(row[0])))
    conn_target.commit()

  cursor_source.close()
  conn_source.close()
  cursor_target.close()
  conn_target.close()

  def sync_table_schema_byname(self, tab_name, is_reference):
  conn_source = self.get_connect(self.s_h, self.s_i, self.s_P, self.s_u, self.s_p, self.s_d)
  conn_target = self.get_connect(self.t_h, self.t_i, self.t_P, self.t_u, self.t_p, self.t_d)
  cursor_source = conn_source.cursor()
  cursor_target = conn_target.cursor()

  if (self.exits_object(conn_source, self.format_object_name(tab_name)) == 0):
    print("----------------------- warning message -----------------------")
    print("---------------warning: object " + tab_name + " not existing in source database ----------------")
    print("----------------------- warning message -----------------------")
    print()
    return

  # if exists a reference table for sp,not sync the table agagin
  if (self.exits_object(conn_target, self.format_object_name(tab_name)) > 0):
    if (self.f != "Y"):
    print("----------------------- warning message -----------------------")
    print("---------------warning: object " + tab_name + " existing in target database ----------------")
    print("----------------------- warning message -----------------------")
    print()
    return

  sql_script = r''' select top 1 1 from sys.tables 
           where type_desc = 'USER_TABLE' 
           and concat(QUOTENAME(schema_name(schema_id)),'.',QUOTENAME(name)) = '{0}' 
         '''.format((self.format_object_name(tab_name)))
  # if the table schema exists in target server,skip
  cursor_target.execute(sql_script)
  exists_in_target = cursor_target.fetchone()


  if exists_in_target:
    if (self.f == "Y"):
    if (is_reference != "Y"):
      cursor_target.execute("drop table {0}".format(tab_name))
    else:
    print("----------------------- warning message -----------------------")
    print("the target table " + tab_name + " exists ,skiped sync table schema from source")
    print("----------------------- warning message -----------------------")
    print()
    return

  sql_script = r'''   DECLARE 
           @object_name SYSNAME
          , @object_id INT

        SELECT 
           @object_name = '[' + s.name + '].[' + o.name + ']'
          , @object_id = o.[object_id]
        FROM sys.objects o WITH (NOWAIT)
        JOIN sys.schemas s WITH (NOWAIT) ON o.[schema_id] = s.[schema_id]
        WHERE QUOTENAME(s.name) + '.' + QUOTENAME(o.name) = '{0}'
          AND o.[type] = 'U'
          AND o.is_ms_shipped = 0

        DECLARE @SQL NVARCHAR(MAX) = ''

        ;WITH index_column AS 
        (
          SELECT 
           ic.[object_id]
          , ic.index_id
          , ic.is_descending_key
          , ic.is_included_column
          , c.name
          FROM sys.index_columns ic WITH (NOWAIT)
          JOIN sys.columns c WITH (NOWAIT) ON ic.[object_id] = c.[object_id] AND ic.column_id = c.column_id
          WHERE ic.[object_id] = @object_id
        ),
        fk_columns AS 
        (
           SELECT 
           k.constraint_object_id
          , cname = c.name
          , rcname = rc.name
          FROM sys.foreign_key_columns k WITH (NOWAIT)
          JOIN sys.columns rc WITH (NOWAIT) ON rc.[object_id] = k.referenced_object_id AND rc.column_id = k.referenced_column_id 
          JOIN sys.columns c WITH (NOWAIT) ON c.[object_id] = k.parent_object_id AND c.column_id = k.parent_column_id
          WHERE k.parent_object_id = @object_id
        )
        SELECT @SQL = 'CREATE TABLE ' + @object_name + '' + '(' + '' + STUFF((
          SELECT '' + ', [' + c.name + '] ' + 
          CASE WHEN c.is_computed = 1
            THEN 'AS ' + cc.[definition] 
            ELSE UPPER(tp.name) + 
            CASE WHEN tp.name IN ('varchar', 'char', 'varbinary', 'binary', 'text')
              THEN '(' + CASE WHEN c.max_length = -1 THEN 'MAX' ELSE CAST(c.max_length AS VARCHAR(5)) END + ')'
               WHEN tp.name IN ('nvarchar', 'nchar')
              THEN '(' + CASE WHEN c.max_length = -1 THEN 'MAX' ELSE CAST(c.max_length / 2 AS VARCHAR(5)) END + ')'
               WHEN tp.name IN ('datetime2', 'time2', 'datetimeoffset') 
              THEN '(' + CAST(c.scale AS VARCHAR(5)) + ')'
               WHEN tp.name = 'decimal' 
              THEN '(' + CAST(c.[precision] AS VARCHAR(5)) + ',' + CAST(c.scale AS VARCHAR(5)) + ')'
              ELSE ''
            END +
            CASE WHEN c.collation_name IS NOT NULL THEN ' COLLATE ' + c.collation_name ELSE '' END +
            CASE WHEN c.is_nullable = 1 THEN ' NULL' ELSE ' NOT NULL' END +
            CASE WHEN dc.[definition] IS NOT NULL THEN ' DEFAULT' + dc.[definition] ELSE '' END + 
            CASE WHEN ic.is_identity = 1 THEN ' IDENTITY(' + CAST(ISNULL( /*ic.seed_value*/ 1, '0') AS CHAR(1)) + ',' + CAST(ISNULL(ic.increment_value, '1') AS CHAR(1)) + ')' ELSE '' END 
          END + ''
          FROM sys.columns c WITH (NOWAIT)
          JOIN sys.types tp WITH (NOWAIT) ON c.user_type_id = tp.user_type_id
          LEFT JOIN sys.computed_columns cc WITH (NOWAIT) ON c.[object_id] = cc.[object_id] AND c.column_id = cc.column_id
          LEFT JOIN sys.default_constraints dc WITH (NOWAIT) ON c.default_object_id != 0 AND c.[object_id] = dc.parent_object_id AND c.column_id = dc.parent_column_id
          LEFT JOIN sys.identity_columns ic WITH (NOWAIT) ON c.is_identity = 1 AND c.[object_id] = ic.[object_id] AND c.column_id = ic.column_id
          WHERE c.[object_id] = @object_id
          ORDER BY c.column_id
          FOR XML PATH(''), TYPE).value('.', 'NVARCHAR(MAX)'), 1, 2, '' + ' ')
          + ISNULL((SELECT '' + ', CONSTRAINT [' + k.name + '] PRIMARY KEY (' + 
              (SELECT STUFF((
               SELECT ', [' + c.name + '] ' + CASE WHEN ic.is_descending_key = 1 THEN 'DESC' ELSE 'ASC' END
               FROM sys.index_columns ic WITH (NOWAIT)
               JOIN sys.columns c WITH (NOWAIT) ON c.[object_id] = ic.[object_id] AND c.column_id = ic.column_id
               WHERE ic.is_included_column = 0
                 AND ic.[object_id] = k.parent_object_id 
                 AND ic.index_id = k.unique_index_id   
               FOR XML PATH(N''), TYPE).value('.', 'NVARCHAR(MAX)'), 1, 2, ''))
            + ')' + ''
            FROM sys.key_constraints k WITH (NOWAIT)
            WHERE k.parent_object_id = @object_id 
            AND k.[type] = 'PK'), '') + ')' + ''
          + ISNULL((SELECT (
          SELECT '' +
             'ALTER TABLE ' + @object_name + ' WITH' 
            + CASE WHEN fk.is_not_trusted = 1 
            THEN ' NOCHECK' 
            ELSE ' CHECK' 
             END + 
             ' ADD CONSTRAINT [' + fk.name + '] FOREIGN KEY(' 
             + STUFF((
            SELECT ', [' + k.cname + ']'
            FROM fk_columns k
            WHERE k.constraint_object_id = fk.[object_id] and 1=2
            FOR XML PATH(''), TYPE).value('.', 'NVARCHAR(MAX)'), 1, 2, '')
            + ')' +
             ' REFERENCES [' + SCHEMA_NAME(ro.[schema_id]) + '].[' + ro.name + '] ('
             + STUFF((
            SELECT ', [' + k.rcname + ']'
            FROM fk_columns k
            WHERE k.constraint_object_id = fk.[object_id]
            FOR XML PATH(''), TYPE).value('.', 'NVARCHAR(MAX)'), 1, 2, '')
            + ')'
            + CASE 
            WHEN fk.delete_referential_action = 1 THEN ' ON DELETE CASCADE' 
            WHEN fk.delete_referential_action = 2 THEN ' ON DELETE SET NULL'
            WHEN fk.delete_referential_action = 3 THEN ' ON DELETE SET DEFAULT' 
            ELSE '' 
             END
            + CASE 
            WHEN fk.update_referential_action = 1 THEN ' ON UPDATE CASCADE'
            WHEN fk.update_referential_action = 2 THEN ' ON UPDATE SET NULL'
            WHEN fk.update_referential_action = 3 THEN ' ON UPDATE SET DEFAULT' 
            ELSE '' 
             END 
            + '' + 'ALTER TABLE ' + @object_name + ' CHECK CONSTRAINT [' + fk.name + ']' + ''
          FROM sys.foreign_keys fk WITH (NOWAIT)
          JOIN sys.objects ro WITH (NOWAIT) ON ro.[object_id] = fk.referenced_object_id
          WHERE fk.parent_object_id = @object_id
          FOR XML PATH(N''), TYPE).value('.', 'NVARCHAR(MAX)')), '')
          + ISNULL(((SELECT
           '' + 'CREATE' + CASE WHEN i.is_unique = 1 THEN ' UNIQUE' ELSE '' END 
            + ' NONCLUSTERED INDEX [' + i.name + '] ON ' + @object_name + ' (' +
            STUFF((
            SELECT ', [' + c.name + ']' + CASE WHEN c.is_descending_key = 1 THEN ' DESC' ELSE ' ASC' END
            FROM index_column c
            WHERE c.is_included_column = 0
              AND c.index_id = i.index_id
            FOR XML PATH(''), TYPE).value('.', 'NVARCHAR(MAX)'), 1, 2, '') + ')' 
            + ISNULL('' + 'INCLUDE (' + 
              STUFF((
              SELECT ', [' + c.name + ']'
              FROM index_column c
              WHERE c.is_included_column = 1
              AND c.index_id = i.index_id
              FOR XML PATH(''), TYPE).value('.', 'NVARCHAR(MAX)'), 1, 2, '') + ')', '') + ''
          FROM sys.indexes i WITH (NOWAIT)
          WHERE i.[object_id] = @object_id
            AND i.is_primary_key = 0
            AND i.[type] = 2
          FOR XML PATH(''), TYPE).value('.', 'NVARCHAR(MAX)')
          ), '')

        select @SQL as script '''.format(self.format_object_name(tab_name))
  cursor_target = conn_target.cursor()
  cursor_source.execute(sql_script)
  row = cursor_source.fetchone()

  if not row[0]:
    return

  try:
    cursor_target.execute(row[0]) # drop current table schema if exists
    conn_target.commit()
    print("*************schema " + self.format_object_name(tab_name) + " synced *************")
    print() # give a blank row when finish
  except:
    print("----------------------- warning message -----------------------")
    print("-----------schema " + self.format_object_name(tab_name) + " synced failed---------------")
    print("----------------------- warning message -----------------------")
    print()

  cursor_source.close()
  conn_source.close()
  cursor_target.close()
  conn_target.close()

  def get_table_column(self, conn, tab_name):
  column_names = ""
  conn = conn
  cursor_source = conn.cursor()
  # get object by name from source db
  sql_script = r'''select name from sys.columns 
       where object_id = object_id('{0}') and is_computed=0 order by object_id
         '''.format(self.format_object_name(tab_name))
  cursor_source.execute(sql_script)
  result = cursor_source.fetchall()
  for row in result:
    column_names = column_names + row[0] + ","

  return column_names[0:len(column_names) - 1]
  conn.cursor.close()
  conn.close()

  def sync_table_schema(self):
  #default not sync by referenced other object
  is_reference = "N"
  conn_source = self.get_connect(self.s_h, self.s_i, self.s_P, self.s_u, self.s_p, self.s_d)
  conn_target = self.get_connect(self.t_h, self.t_i, self.t_P, self.t_u, self.t_p, self.t_d)
  cursor_source = conn_source.cursor()
  cursor_target = conn_target.cursor()
  arr_table = []
  if (self.s_obj):
    for tab_name in self.s_obj.split(","):
    if (tab_name) and (self.exits_object(conn_source, tab_name)>0):
      self.sync_table_schema_byname(tab_name, is_reference)
    else:
      print("----------------------- warning message -----------------------")
      print("-----------schema " + self.format_object_name(tab_name) + " not existing in source database---------------")
      print("----------------------- warning message -----------------------")
      print()
  else:
    # sync all tables
    # get all table in database when not define table name
    sql_script = ''' SELECT QUOTENAME(s.name)+'.'+ QUOTENAME(o.name)
         FROM sys.objects o WITH (NOWAIT)
         JOIN sys.schemas s WITH (NOWAIT) ON o.[schema_id] = s.[schema_id]
         WHERE o.[type] = 'U' AND o.is_ms_shipped = 0
       '''
    cursor_source.execute(sql_script)
    for row in cursor_source.fetchall():
    self.sync_table_schema_byname(str(row[0]), is_reference)

  # sync data from soure table to target table
  def sync_table_data(self):
  conn_source = self.get_connect(self.s_h, self.s_i, self.s_P, self.s_u, self.s_p, self.s_d)
  conn_target = self.get_connect(self.t_h, self.t_i, self.t_P, self.t_u, self.t_p, self.t_d)
  cursor_source = conn_source.cursor()
  cursor_target = conn_target.cursor()
  arr_table = []
  if (self.s_obj):
    arr_table = self.s_obj.split(',')
    for tab_name in arr_table:
    if (self.exits_object(conn_target, self.format_object_name(tab_name)) == 0):
      arr_table.remove(tab_name)
      print("----------------- warning message -----------------------")
      print("----------------- warning: table " + tab_name + " not existing in target database ---------------------")
      print("----------------- warning message -----------------------")
  else:
    # get all table in database when not define table name
    tab_result = cursor_source.execute(r''' SELECT QUOTENAME(s.name)+'.'+ QUOTENAME(o.name)
              FROM sys.objects o WITH (NOWAIT)
              JOIN sys.schemas s WITH (NOWAIT) ON o.[schema_id] = s.[schema_id]
              WHERE o.[type] = 'U'
              AND o.is_ms_shipped = 0
            ''')
    for row in cursor_source.fetchall():
    arr_table.append(str(row[0]))

  insert_columns = ""
  insert_columns = self.get_table_column(conn_source, tab_name)

  for tab_name in arr_table:
    if (self.f != "Y"):
    sql_script = "select top 1 {0} from {1} ".format(insert_columns, tab_name)
    # if exists data in target table,break
    cursor_target.execute(sql_script)
    exists = cursor_target.fetchone()
    if exists:
      print("----------------------- warning message -----------------------")
      print("the target table " + tab_name + " exists data,skiped sync table type from source")
      print("----------------------- warning message -----------------------")
      print()
      continue
    else:
    sql_script = "truncate table {0} ".format(tab_name)
    # if exists data in target table,break
    cursor_target.execute(sql_script)
    conn_target.commit()

    insert_columns = ""
    insert_columns = self.get_table_column(conn_source, tab_name)

    insert_prefix = ""

    # weather has identity column
    cursor_source.execute(r'''select 1 from sys.columns 
          where object_id = OBJECT_ID('{0}') and is_identity =1
          '''.format(tab_name))
    exists_identity = None
    exists_identity = cursor_source.fetchone()
    if (exists_identity):
    insert_prefix = "set identity_insert {0} on; ".format(tab_name)

    # data source
    insert_sql = ""
    values_sql = ""
    current_row = ""
    counter = 0
    sql_script = r''' select {0} from {1}  '''.format(insert_columns, tab_name)
    cursor_source.execute(sql_script)

    # create insert columns
    '''
    for field in cursor_source.description:
    insert_columns = insert_columns + str(field[0]) + ","
    insert_columns = insert_columns[0:len(insert_columns) - 1]
    '''
    insert_prefix = insert_prefix + "insert into {0} ({1}) values ".format(tab_name, insert_columns)

    for row in cursor_source.fetchall():
    counter = counter + 1
    for key in row:
      if (str(key) == "None"):
      current_row = current_row + r''' null, '''
      else:
      if (type(key) is datetime.datetime):
        current_row = current_row + r''' '{0}', '''.format(str(key)[0:23])
      elif (type(key) is str):
        # 我槽!!!,这里又有一个坑:https://blog.csdn.net/dadaowuque/article/details/81016127
        current_row = current_row + r''' '{0}', '''.format(
        key.replace("'", "''").replace('\u0000', '').replace('\x00', ''))
      elif (type(key) is Decimal):
        d = Decimal(key)
        s = '{0:f}'.format(d)
        current_row = current_row + r''' '{0}', '''.format(s)
      elif (type(key) is bytes):
        # print(hex(int.from_bytes(key, 'big', signed=True) ))
        current_row = current_row + r''' {0}, '''.format(
        hex(int.from_bytes(key, 'big', signed=False)))
      else:
        current_row = current_row + r''' '{0}', '''.format(key)

    current_row = current_row[0:len(current_row) - 2] # remove the the last one char ","
    values_sql = values_sql + "(" + current_row + "),"
    current_row = ""

    # execute the one batch when
    if (counter == 1000):
      insert_sql = insert_prefix + values_sql
      insert_sql = insert_sql[0:len(insert_sql) - 1] # remove the the last one char ","
      if (exists_identity):
      insert_sql = insert_sql + " ;set identity_insert {0} off;".format(tab_name)
      try:
      cursor_target.execute(insert_sql)
      except:
      print(
        "----------------------error " + tab_name + " data synced failed-------------------------")
      raise

      conn_target.commit()
      insert_sql = ""
      values_sql = ""
      current_row = ""
      counter = 0
      print(time.strftime("%Y-%m-%d %H:%M:%S",
          time.localtime()) + "*************** " + self.format_object_name(
      tab_name) + " " + str(1000) + " rows synced *************")

    if (values_sql):
    insert_sql = insert_prefix + values_sql
    insert_sql = insert_sql[0:len(insert_sql) - 1] # remove the the last one char ","
    if (exists_identity):
      insert_sql = insert_sql + " ; set identity_insert {0} off;".format(tab_name)
    # execute the last batch
    try:
      cursor_target.execute(insert_sql)
    except:
      print("------------------error " + tab_name + " data synced failed------------------------")
      raise

    conn_target.commit()
    insert_sql = ""
    values_sql = ""
    current_row = ""
    print(time.strftime("%Y-%m-%d %H:%M:%S",
          time.localtime()) + "*************** " + self.format_object_name(
      tab_name) + " " + str(
      counter) + " rows synced *************")
    print(time.strftime("%Y-%m-%d %H:%M:%S",
          time.localtime()) + "----------------synced " + self.format_object_name(
      tab_name) + " data finished---------------")
    print()
  cursor_source.close()
  conn_source.close()
  cursor_target.close()
  conn_target.close()

  def sync_dependent_object(self, obj_name):
  # 强制覆盖,不需要对依赖对象生效,如果是因为属于依赖对象而被同步的,先检查target中是否存在,如果存在就不继续同步,这里打一个标记来实现
  is_refernece = "Y"
  conn_source = self.get_connect(self.s_h, self.s_i, self.s_P, self.s_u, self.s_p, self.s_d)
  conn_target = self.get_connect(self.t_h, self.t_i, self.t_P, self.t_u, self.t_p, self.t_d)
  cursor_source = conn_source.cursor()
  cursor_target = conn_target.cursor()
  '''
  find dependent objects
  if exists dependent objects,sync Dependent objects objects in advance
  '''
  sql_check_dependent = r'''     
         SELECT * FROM
        (
        SELECT
        distinct rtrim(lower(s.type)) COLLATE Chinese_PRC_CI_AS as obj_type, 
        QUOTENAME(d.referenced_schema_name)+'.'+QUOTENAME(d.referenced_entity_name) COLLATE Chinese_PRC_CI_AS as obj
        FROM sys.dm_sql_referenced_entities('{0}','OBJECT') as d
          inner join sys.sysobjects s on s.id = d.referenced_id
        union all
        SELECT
        distinct rtrim(lower(d.referenced_class_desc)) COLLATE Chinese_PRC_CI_AS as obj_type,
        QUOTENAME(d.referenced_schema_name)+'.'+QUOTENAME(d.referenced_entity_name) COLLATE Chinese_PRC_CI_AS as obj
        FROM sys.dm_sql_referenced_entities('{0}','OBJECT') as d
          inner join sys.types s on s.user_type_id = d.referenced_id
        )t
         '''.format(self.format_object_name(obj_name))

  cursor_source.execute(sql_check_dependent)
  result = cursor_source.fetchall()
  for row in result:
    if row[1]:
    if (row[0] == "u"):
      if (row[1]):
      self.sync_table_schema_byname(row[1], is_refernece)
    elif (row[0] == "fn" or row[0] == "if"):
      if (row[1]):
      self.sync_procudre_by_name("f", row[1], is_refernece)
    elif (row[0] == "type"):
      if (row[1]):
      self.sync_table_variable(row[1], is_refernece)

  def sync_procudre_by_name(self, type, obj_name, is_reference):
  conn_source = self.get_connect(self.s_h, self.s_i, self.s_P, self.s_u, self.s_p, self.s_d)
  conn_target = self.get_connect(self.t_h, self.t_i, self.t_P, self.t_u, self.t_p, self.t_d)
  cursor_source = conn_source.cursor()
  cursor_target = conn_target.cursor()

  if (self.exits_object(conn_source, self.format_object_name(obj_name)) == 0):
    print("---------------warning message----------------")
    print("---------------warning: object " + obj_name + " not existing in source database ----------------")
    print("---------------warning message----------------")
    print()
    return

  if (self.exits_object(conn_target, self.format_object_name(obj_name)) > 0):
    if (self.f != "Y"):
    print("---------------warning message----------------")
    print("---------------warning: object " + obj_name + " existing in target database ----------------")
    print("---------------warning message----------------")
    print()
    return

  ''' 
  本来想直接生成删除语句的:  
  这里有一个该死的转义,怎么都弄不好,中午先去吃饭吧,
  下午回来想了一下,换一种方式,不要死磕转义问题了
  sql_script = 
      select
      'if object_id('+''''+QUOTENAME(schema_name(uid))+ '' + QUOTENAME(name)+''''+') is not null '
      +' drop proc '+QUOTENAME(schema_name(uid))+ '.' + QUOTENAME(name) ,
      OBJECT_DEFINITION(id)
      from sys.sysobjects where xtype = 'P' and uid not in (16,19)

  '''
  sql_script = r'''
      select
      QUOTENAME(schema_name(uid))+'.'+QUOTENAME(name),
      OBJECT_DEFINITION(id)
      from sys.sysobjects where xtype in ('P','IF','FN') and uid not in (16,19)
     '''
  if (obj_name):
    sql_script = sql_script + " and QUOTENAME(schema_name(uid))+ '.' + QUOTENAME(name) ='{0}' ".format(
    self.format_object_name(obj_name))

  cursor_source.execute(sql_script)
  row = cursor_source.fetchone()
  try:
    if type == "f":
    sql_script = r'''
        if object_id('{0}') is not null 
          drop function {0}
        '''.format(self.format_object_name(row[0]))
    elif type == "p":
    sql_script = r'''
        if object_id('{0}') is not null 
          drop proc {0}
        '''.format(self.format_object_name(row[0]))

    cursor_target.execute(sql_script) # drop current stored_procudre if exists
    conn_target.commit()

    # sync dependent object
    if (is_reference != "N"):
    self.sync_dependent_object(self.format_object_name(row[0]))

    # sync object it self
    cursor_target.execute(str(row[1])) # execute create stored_procudre script
    conn_target.commit()
    print("*************sync sp: " + self.format_object_name(row[0]) + " finished *****************")
    print()
  except:
    print("---------------error message----------------")
    print("------------------ sync " + row[0] + "sp error --------------------------")
    print("---------------error message----------------")
    print()

  cursor_source.close()
  conn_source.close()
  cursor_target.close()
  conn_target.close()

  def sync_procudre(self, type):
  is_reference = "N"
  conn_source = self.get_connect(self.s_h, self.s_i, self.s_P, self.s_u, self.s_p, self.s_d)
  conn_target = self.get_connect(self.t_h, self.t_i, self.t_P, self.t_u, self.t_p, self.t_d)
  cursor_source = conn_source.cursor()
  cursor_target = conn_target.cursor()
  if (self.s_obj):
    for proc_name in self.s_obj.split(","):
    self.sync_dependent_object(proc_name)
    self.sync_procudre_by_name(type, proc_name, is_reference)
  # sync all sp and function
  else:
    sql_script = r'''
      select
      QUOTENAME(schema_name(uid))+'.'+QUOTENAME(name),
      OBJECT_DEFINITION(id)
      from sys.sysobjects where xtype = upper('{0}') and uid not in (16,19)
       '''.format(type)
    cursor_source.execute(sql_script)
    for row in cursor_source.fetchall():
    self.sync_dependent_object(row[0])
    self.sync_procudre_by_name(type, row[0], is_reference)


if __name__ == "__main__":

  '''
  sync = SyncDatabaseObject(s_h="127.0.0.1",
         s_i = "sql2017",
         s_P = 49744,
         s_d="DB01",

         t_h="127.0.0.1",
         t_i="sql2017",
         t_P=49744,
         t_d="DB02",

         s_obj_type = "sp",
         s_obj = "dbo.sp_test01",

         f="Y")
  sync.sync_procudre("p")
  '''

  p_s_h = ""
  p_s_i = "MSSQL"
  p_s_P = 1433
  p_s_d = ""

  p_s_u = None
  p_s_p = None

  p_s_obj = ""
  p_type = ""

  p_t_s = ""
  p_t_i = "MSSQL"
  p_t_P = "1433"
  p_t_d = ""

  p_t_u = None
  p_t_p = None

  # force conver target database object,default not force cover target database object
  p_f = "N"

  # sync obj type table|sp
  p_obj_type = None
  # sync whick database object
  p_obj = None

  if len(sys.argv) == 1:
  print(usage)
  sys.exit(1)
  elif sys.argv[1] == '--help':
  print(usage)
  sys.exit()
  elif len(sys.argv) >= 2:
  for i in sys.argv[1:]:
    _argv = i.split('=')

    # source server name
    if _argv[0] == '-s_h':
    p_s_h = _argv[1]
    # source server instance name
    if _argv[0] == '-s_i':
    if (_argv[1]):
      p_s_i = _argv[1]
    # source server instance PORT
    if _argv[0] == '-s_P':
    if (_argv[1]):
      p_s_P = _argv[1]
    # source database name
    if _argv[0] == '-s_d':
    p_s_d = _argv[1]

    if _argv[0] == '-s_u':
    p_s_u = _argv[1]

    if _argv[0] == '-s_p':
    p_s_p = _argv[1]

    if _argv[0] == '-t_h':
    p_t_h = _argv[1]

    if _argv[0] == '-t_i':
    if (_argv[1]):
      p_t_i = _argv[1]

    if _argv[0] == '-t_P':
    if (_argv[1]):
      p_t_P = _argv[1]

    if _argv[0] == '-t_d':
    p_t_d = _argv[1]

    if _argv[0] == '-t_u':
    p_t_u = _argv[1]

    if _argv[0] == '-t_p':
    p_t_p = _argv[1]

    if _argv[0] == '-f':
    if (_argv[1]):
      p_f = _argv[1]

    # object type
    if _argv[0] == '-obj_type':
    if not (_argv[1]):
      print("-obj_type can not be null (-obj=tab|-obj=sp|-obj=fn|-obj=type)")
      exit(0)
    else:
      p_obj_type = _argv[1]

    # object name
    if _argv[0] == '-obj':
    if (_argv[1]):
      p_obj = _argv[1]

  # require para
  if p_s_h.strip() == "":
    print("source server host cannot be null")
    exit(0)
  if p_s_d.strip() == "":
    print("source server host database name cannot be null")
    exit(0)

  if p_t_h.strip() == "":
    print("target server host cannot be null")
    exit(0)

  if p_t_d.strip() == "":
    print("target server host database name cannot be null")
    exit(0)

  sync = SyncDatabaseObject(s_h=p_s_h,
         s_i=p_s_i,
         s_P=p_s_P,
         s_d=p_s_d,
         s_u=p_s_u,
         s_p=p_s_p,

         s_obj=p_obj,

         t_h=p_t_h,
         t_i=p_t_i,
         t_P=p_t_P,
         t_d=p_t_d,
         t_u=p_t_u,
         t_p=p_t_p,

         f=p_f)

  sync.validated_connect(p_s_h, p_s_i, p_s_P, p_s_d, p_s_u, p_s_p)
  sync.validated_connect(p_t_h, p_t_i, p_t_P, p_t_d, p_t_u, p_t_p)

  if (p_f.upper() == "Y"):
    confirm = input("confirm you want to overwrite the target object?")
    if confirm.upper() != "Y":
    exit(0)

  print("-------------------------- sync begin ----------------------------------")
  print()

  if (p_obj_type == "tab"):
    # sync schema
    sync.sync_schema()
    # sync table schema
    sync.sync_table_schema()
    # sync data
    sync.sync_table_data()
  elif (p_obj_type == "sp"):
    # sync schema
    sync.sync_schema()
    # sync sp
    sync.sync_procudre("p")
  elif (p_obj_type == "fn"):
    # sync schema
    sync.sync_schema()
    # sync sp
    sync.sync_procudre("fn")
  elif (p_obj_type == "tp"):
    # sync schema
    sync.sync_schema()
    # sync sp
    sync.sync_table_variable()
  else:
    print("-obj_type is not validated")

  print()
  print("-------------------------- sync finish ----------------------------------")
  总结
  以上所述是小编给大家介绍的基于Python的SQL Server数据库实现对象同步轻量级,希望对大家有所帮助,如果大家有任何疑问欢迎给我留言,小编会及时回复大家的!

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