Sql 为什么值发生更改我们可以查询此表以查看什么/什么时候发生了更改。在这种情况下，您可以直接使用distinct对除RunKey和Rundate之外的所有列进行查询，然后将该表与该行数据的min（Rundate）和min（RunKey）进行自联接。这类似于“只

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为什么值发生更改我们可以查询此表以查看什么/什么时候发生了更改。在这种情况下，您可以直接使用distinct对除RunKey和Rundate之外的所有列进行查询，然后将该表与该行数据的min（Rundate）和min（RunKey）进行自联接。这类似于“只插入更改”，这是一个更好的想法。也就是说，不是用未更改的行归档该表，而是在有更改时才插入。这将减小表的大小，并消除您正在创建的额外表。这是否符合业务需求？是否有一种方法也可以捕获旧的价值？这是这里的关键，他想知道更改日期、旧值和新值，以及更改的列。因此，与插入包含更改的整行不同，他们只想查看更改的特定列、更改日期以及新旧值。更改日期是runDate，假设您每天都运行它。因此，只有更改了才会得到新行，并且日期将是getdate（），它将显示更改的日期。从另一个角度来看，这真的是走了太多的4步。这种方法向您显示更改以及更改的时间，仅在更改时显示。它解决了核心问题，而不必为糟糕的设计使用解决方案IMHO@bm11是的，触发器既可以访问旧值，也可以访问新值。我用实际样本数据对此进行了测试，效果非常好。我正在用大约900k行的完整数据集进行测试。它运行得非常慢，因为我有26列要跟踪更改，而且似乎cte0会为每个运行键的每一列生成一行。@bm11请参阅编辑第二个选项。我将脚本添加到一个光标上，该光标在帐号上迭代并插入到我的表中。适用于所有以前的记录，并将继续创建触发器。您知道如何使用触发器提取列名吗？当我运行nightly insert时，我希望它在帐号级别查看最新的RunKey并进行比较，以查看是否发生了任何更改。 |AccountNo | RunKey | RunDate | Address | Salary | PromotionDate| ---------------------------------------------------------------------------- | 12345 | 2 | 06/20/2017 | 123 Main Street | 60,000 | 01/15/2017 | | 12345 | 3 | 06/21/2017 | 123 Main Street | 60,000 | 01/15/2017 | | 12345 | 4 | 06/22/2017 | 123 Main Street | 65,000 | 06/21/2017 | |AccountNo | RunKey | RunDate | Address | AddressLAG |AddressFlag| Salary | SalaryLAG |SalaryFlag| PromotionDate|PromotionDateLag|PromotionFlag| ----------------------------------------------------------------------------------------------------------------------------------------------------------------- | 12345 | 2 | 06/20/2017 | 123 Main Street | 123 Main Street | 0 | 60,000 | 60,000 | 0 | 01/15/2017 | 01/15/2017 | 0 | | 12345 | 3 | 06/21/2017 | 123 Main Street | 123 Main Street | 0 | 60,000 | 60,000 | 0 | 01/15/2017 | 01/15/2017 | 0 | | 12345 | 4 | 06/22/2017 | 123 Main Street | 123 Main Street | 0 | 65,000 | 60,000 | 1 | 01/15/2017 | 06/21/2017 | 1 | | RunKey | AccountNo | ChangedCol | PrevRunDate | RunDate | PrevValue | NewValue | ------------------------------------------------------------------------------------------- | 4 | 12345 | Salary | 06/21/2017 | 06/22/2017 | 60,000 | 65,000 | | 4 | 12345 | PromotionDate | 06/21/2017 | 06/22/2017 | 01/15/2017 | 06/21/2017 |

declare @source table (
                        AccountNo int
                        ,Address varchar(256)
                        ,Salary decimal(16,4)
                        ,PromotionDate datetime)
insert into @source
values
(12345,'123 Main Street',60000,'20170115')


declare @audit table (
                        AccountNo int
                        ,Address varchar(256)
                        ,Salary decimal(16,4)
                        ,PromotionDate datetime
                        ,RunDate datetime)

--load the audit table with the current version of the source table
insert into @audit
select *, getdate() from @source

--show that the tables match currently
select * from @source
select * from @audit

--insert into @audit if there are any changes (notice we haven't made any updates yet)
insert into @audit
select AccountNo, Address, Salary, PromotionDate, getdate() from @source
except 
select AccountNo, Address, Salary, PromotionDate, getdate() from @audit

--show that a record WAS NOT inserted since there was no change. There is only 1 record, the orignal version
select * from @audit

--update the promotion and salary
update @source
set
    PromotionDate = '20170331'
    ,Salary = '65000'

--insert into @audit if there are any changes
insert into @audit
select AccountNo, Address, Salary, PromotionDate, getdate() from @source
except 
select AccountNo, Address, Salary, PromotionDate, getdate() from @audit

--show that a record was inserted since there was a change
select * from @audit

Declare @YourTable Table ([AccountNo] int,[RunKey] int,[RunDate] date,[Address] varchar(50),[Salary] int,[PromotionDate] date)
Insert Into @YourTable Values 
 (12345,2,'06/20/2017','123 Main Street',60000,'01/15/2017')
,(12345,3,'06/21/2017','123 Main Street',60000,'01/15/2017')
,(12345,4,'06/22/2017','123 Main Street',65000,'06/21/2017')


;with cte as (
    Select A.AccountNo
          ,A.RunKey
          ,A.RunDate
          ,B.*
         ,PreValue=Lag(Value)   over (Partition By AccountNo,Item Order by RunDate) 
         ,PreDate =Lag(RunDate) over (Partition By AccountNo,Item Order by RunDate) 
     From  @YourTable A
     Cross Apply ( values ('Address'      ,cast(A.[Address] as varchar(max)))
                         ,('Salary'       ,cast(A.[Salary]  as varchar(max)))
                         ,('PromotionDate',cast(A.[PromotionDate] as varchar(max)))
                 ) B (Item,Value)
)
Select *
 From  cte
 Where Value<>PreValue and PreValue is not null