Question

我正在创建一个使用CDC维护包含历史数据的表的设置。以下是我写的脚本：

create table dbo.Name (ID int not null primary key clustered identity(1,1),
Col1 nvarchar(50) not null constraint DF_Col1 default 'Unknown',
Col2 nvarchar(50) not null constraint DF_Col2 default 'Unknown',
Col3 nvarchar(50) not null constraint DF_Col3 default 'Unknown',
Col4 nvarchar(50) not null constraint DF_Col4 default 'Unknown',
Col5 nvarchar(50) not null constraint DF_Col5 default 'Unknown',
CreatedDate DATETIME NOT NULL DEFAULT(GETDATE()),
ModifiedDate DATETIME 
)
GO

exec sys.sp_cdc_enable_db
go
exec sys.sp_cdc_enable_table @source_schema = N'dbo',
@source_name = N'Name',
@capture_instance = 'Name', 
@supports_net_changes = 1, 
@role_name = NULL
GO

INSERT INTO dbo.Name 
VALUES('A','B','C','D','E',GETDATE(),NULL),
('F','G','H','I','J',GETDATE(),NULL),
('K','L','M','N','O',GETDATE(),NULL)
GO

SELECT * FROM cdc.Name_CT

UPDATE Name
SET Col1 = Col1 + '_U', ModifiedDate = GETDATE()
WHERE id = 1

UPDATE Name
SET Col2 = Col2 + '_V', ModifiedDate = GETDATE()
WHERE id = 2 

UPDATE Name
SET Col3 = Col3 + '_A', Col4 = Col4 + '_B', ModifiedDate = GETDATE()
WHERE id = 3
GO

SELECT * FROM cdc.Name_CT

上述脚本将返回数据已更改的列的值。我正在寻找下面的输出，即列FieldName将包含更新数据的列列表，值列将包含前一个和新值。 CreatedDate值将成为更新前行的StartDate，ModifiedDate将成为更新行之前的EndDate和更新行之后的StartDate。

ID    FieldName    Value    StartDate                 EndDate
=================================================================
1     Col1         A        2014-08-18 15:56:08       2014-08-18 15:59:44
1     Col1         A_U      2014-08-18 15:59:44       NULL
2     Col2         G        2014-08-18 15:56:08       2014-08-18 15:59:44
2     Col2         G_V      2014-08-18 15:59:44       NULL
3     Col3         M        2014-08-18 15:56:08       2014-08-18 15:59:44
3     Col3         M_A      2014-08-18 15:59:44       NULL
3     Col4         N        2014-08-18 15:56:08       2014-08-18 15:59:44
3     Col4         N_B      2014-08-18 15:59:44       NULL

Answer 1

我认为通过使用表cdc.Name_CT上的pivot函数，您可以获得所需的输出结构。

Answer 2

我在我的表格中查询了您的查询，我可以获得多次更新相同行的结果。

With Cte_CDC as (SELECT ID,FieldName,FieldValue,StartDate=CreatedDate,EndDate 

=ModifiedDate
from 
(
Select ID,Col1,Col2,Col3,Col4,Col5,CreatedDate,ModifiedDate 
FROM cdc.mssqlserver2012_ct
) a
Unpivot
(
FieldValue for FieldName in (Col1,Col2,Col3,Col4,Col5)
) Upt)


select distinct a.ID,a.FieldName,a.FieldValue,ISNULL(a.EndDate,a.StartDate) as Startdate,b.EndDate
from Cte_CDC a
join Cte_CDC b on a.ID=b.ID and a.FieldName=b.FieldName and a.FieldValue<>b.FieldValue
order by 1,2

ID  FieldName   FieldValue  Startdate   EndDate
1   Col1    A   2014-08-20 15:09:40.560 2014-08-20 15:11:34.863
1   Col1    A   2014-08-20 15:09:40.560 2014-08-20 15:12:46.117
1   Col1    A   2014-08-20 15:09:40.560 2014-08-20 15:18:15.973
1   Col1    A_U 2014-08-20 15:11:34.863 NULL
1   Col1    A_U 2014-08-20 15:11:34.863 2014-08-20 15:12:46.117
1   Col1    A_U 2014-08-20 15:11:34.863 2014-08-20 15:18:15.973
1   Col1    A_U_UV  2014-08-20 15:12:46.117 NULL
1   Col1    A_U_UV  2014-08-20 15:12:46.117 2014-08-20 15:11:34.863
1   Col1    A_U_UV  2014-08-20 15:12:46.117 2014-08-20 15:18:15.973
1   Col1    A_U_UV_UVX  2014-08-20 15:18:15.973 NULL
1   Col1    A_U_UV_UVX  2014-08-20 15:18:15.973 2014-08-20 15:11:34.863
1   Col1    A_U_UV_UVX  2014-08-20 15:18:15.973 2014-08-20 15:12:46.117
2   Col2    G   2014-08-20 15:09:40.560 2014-08-20 15:11:34.877
2   Col2    G_V 2014-08-20 15:11:34.877 NULL
3   Col3    M   2014-08-20 15:09:40.560 2014-08-20 15:11:34.877
3   Col3    M_A 2014-08-20 15:11:34.877 NULL
3   Col4    N   2014-08-20 15:09:40.560 2014-08-20 15:11:34.877
3   Col4    N_B 2014-08-20 15:11:34.877 NULL

如果你仍然没有得到，只需交叉检查你的跟踪表天气它是否正确填充每次更新，并验证你的论坛为你的表启用cdc。

使用CDC查找更新的列列表和数据

2 个答案: