如何使用Sql Server 2008比较不同数据库中两个表之间的数据? [英] How to compare data between two table in different databases using Sql Server 2008?

问题描述

我在 Sql server 2008 中有两个数据库，分别命名为 DB1 和 DB2.这两个数据库具有相同的表和相同的表数据.但是，我想检查这些表中的数据之间是否存在差异.

I have two database's, named DB1 and DB2 in Sql server 2008. These two database's have the same tables and same table data also. However, I want to check if there are any differences between the data in these tables.

谁能帮我写一个脚本?

推荐答案

select * 
from (
      select 'T1' T, *
      from DB1.dbo.Table
      except
      select 'T2' T, *
      from DB2.dbo.Table
     ) as T
union all
select * 
from (
      select 'T2' T, *
      from DB2.dbo.Table
      except
      select 'T1' T, *
      from DB1.dbo.Table
     ) as T
ORDER BY 2,3,4, ..., 1  -- make T1 and T2 to be close in output 2,3,4 are UNIQUE KEY SEGMENTS

测试代码:

declare @T1 table (ID int)
declare @T2 table (ID int)

insert into @T1 values(1),(2)
insert into @T2 values(2),(3)

select * 
from (
      select *
      from @T1
      except
      select *
      from @T2
     ) as T
union all
select * 
from (
      select *
      from @T2
      except
      select *
      from @T1
     ) as T

结果:

ID
-----------
1
3

注意:在开发tuned"时，比较大表可能需要很长时间.解决方案或重构，这将给出与 REFERERCE 相同的结果 - 首先检查简单参数可能是明智的:像

Note: It can take long time to compare big table, when developing "tuned" solution or refactorig, which will give same result as REFERERCE - it may be wise to chekc simple parameters first: like

select count(t.*) from (
   select count(*) c0, SUM(BINARY_CHECKSUM(*)%1000000) c1 FROM T_REF_TABLE 
   -- select 12345 c0, -214365454 c1 -- constant values FROM T_REF_TABLE 
   except 
   select count(*) , SUM(BINARY_CHECKSUM(*)%1000000) FROM T_WORK_COPY 
) t

当此项为空时，您可能已经掌握了一些东西，并且您可能会在失败时进行修改，您将看到来自 T_REF 的常量值"；为下一次检查节省更多时间！！！

When this is empty, you have probably things under controll, and may be you can modify when you fail you will see "constant values FROM T_REF" to isert to save even more time for next check!!!

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