SQL 2008 变化跟踪和检测更新数据

Question

我计划在 SSIS 项目中实现它。由于我没有企业版的SQLserver 2008，只好借助其他方法

另一种方法是使用触发器，但我尽量避免使用很多触发器。

使用更改跟踪，我很难检测到正确的操作。该操作被标记为 "I"，而它应该是 "U"。我做错了什么？

这是一个小示例代码。 pKey = 2 应该是 "U"

use master;
go

create database CT_Example;
go

use CT_Example;
go

alter database CT_Example
set change_tracking = on
(change_retention = 2 days, auto_cleanup = on);
go

create table Employee 
(
pKey int not null,
Name nvarchar(50) NULL,
CT bigint null,
constraint pk_pKey 
    primary key (pKey)
);
go

alter table Employee
enable change_tracking
with (track_columns_updated = off);
go

create table Staging 
(
pKey int not null,
Name nvarchar(50) NULL,
CT bigint null,
);
go

insert into Employee (pKey,Name)
values
(1,'Jhon'),
(2,'Phill'),
(3,'Jones'),
(4,'Tom');
go

update e set
    Name = 'Harry'
from
    Employee as e
where
    pKey = 2;
go

update a set
    a.CT = CHANGE_TRACKING_CURRENT_VERSION()
from
    Employee as a;

update e set
    Name = 'Gabriel'
from
    Employee as e
where
    pKey = 2;

insert into Employee (pKey,Name)
values
(5,'Sing'),
(6,'Emily'),
(7,'Jane'),
(8,'Sami');
go

Delete
from
    Employee
where
    pKey = 3;

declare @last_synchronization_version integer;
SET @last_synchronization_version = (select ct from Staging);


select 
    *
from
    Employee as a
    right outer join changetable (changes Employee, @last_synchronization_version) as c
        on a.pKey = c.pKey;
go

use master;
go

drop database CT_Example;
go

Answer 1

你的问题出在这里：

declare @last_synchronization_version integer;
SET @last_synchronization_version = (select ct from Staging);

并且暂存 table 是空的，也是 @last_synchronization_version = NULL。它也应该声明为 bigint.

尝试运行这个：

select 
    *
from
    Employee as a
    right outer join changetable (changes Employee, 3) as c
        on a.pKey = c.pKey;
go

您将看到 pKey=2 的行作为 U。

或者您可以这样请求 "What was the last change operation for row pKey=2?"：

SELECT @last_synchronization_version = sys_change_version - 1 
       FROM changetable (VERSION Employee,([pKey]), (2)) y
SELECT sys_change_operation 
       FROM changetable (changes Employee,  @last_synchronization_version) x 
       WHERE x.pKey=2

可以看到不需要每一行都存储最后一个版本变化，它是由SQL服务器提供的。

As per documentation changetable (changes Employee, null) 应执行以下操作：

If the value is NULL, all tracked changes are returned.

但也许不是最新版本的更改，而是每行所有可用更改的第一个版本。

您可以试试这个脚本，看看更改跟踪是如何工作的：

use master;
go

create database CT_Example;
go

use CT_Example;
go

alter database CT_Example
set change_tracking = on
(change_retention = 2 days, auto_cleanup = on);
go

create table Employee 
(
pKey int not null,
Name nvarchar(50) NULL,
CT bigint null,
constraint pk_pKey 
    primary key (pKey)
);
go

alter table Employee
enable change_tracking
with (track_columns_updated = off);
go


declare @last_synchronization_version bigint;

insert into Employee (pKey,Name)
values
(1,'Jhon'),
(2,'Phill'),
(3,'Jones'),
(4,'Tom');


SELECT CHANGE_TRACKING_CURRENT_VERSION()
SET @last_synchronization_version = CHANGE_TRACKING_CURRENT_VERSION()-1 
SELECT * FROM changetable (changes Employee, @last_synchronization_version) x

update e set
    Name = 'Harry'
from
    Employee as e
where
    pKey = 2;



SELECT CHANGE_TRACKING_CURRENT_VERSION()
SET @last_synchronization_version = CHANGE_TRACKING_CURRENT_VERSION()-1 
SELECT * FROM changetable (changes Employee, @last_synchronization_version) x


update e set
    Name = 'Gabriel'
from
    Employee as e
where
    pKey = 2;

SELECT CHANGE_TRACKING_CURRENT_VERSION()
SET @last_synchronization_version = CHANGE_TRACKING_CURRENT_VERSION()-1 
SELECT * FROM changetable (changes Employee, @last_synchronization_version) x


insert into Employee (pKey,Name)
values
(5,'Sing'),
(6,'Emily'),
(7,'Jane'),
(8,'Sami');

SELECT CHANGE_TRACKING_CURRENT_VERSION()
SET @last_synchronization_version = CHANGE_TRACKING_CURRENT_VERSION()-1 
SELECT * FROM changetable (changes Employee, @last_synchronization_version) x

Delete
from
    Employee
where
    pKey = 3;

SELECT CHANGE_TRACKING_CURRENT_VERSION()
SET @last_synchronization_version = CHANGE_TRACKING_CURRENT_VERSION()-1 
SELECT * FROM changetable (changes Employee,  @last_synchronization_version) x

SET @last_synchronization_version = @last_synchronization_version-1 
SELECT @last_synchronization_version 
SELECT * FROM changetable (changes Employee,  @last_synchronization_version) x

SET @last_synchronization_version = @last_synchronization_version-1 
SELECT @last_synchronization_version 
SELECT * FROM changetable (changes Employee,  @last_synchronization_version) x

SET @last_synchronization_version = @last_synchronization_version-1 
SELECT @last_synchronization_version 
SELECT * FROM changetable (changes Employee,  @last_synchronization_version) x

SET @last_synchronization_version = @last_synchronization_version-1 
SELECT @last_synchronization_version 
SELECT * FROM changetable (changes Employee,  @last_synchronization_version) x

use master;
go

drop database CT_Example;
go

SQL 2008 变化跟踪和检测更新数据

SQL 2008 Change tracking and detecting Updated data

sql

versioning

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