articles >> general dba >> Capture DDL Changes using Change Data Capture ...

Capture DDL Changes using Change Data Capture with SQL Server 2008

By : Ashish Kumar Mehta Jul 23, 2008

Page 2 / 2


How to Configure CDC for a SQL Server 2008 Database Table
1. Now let’s create the Currency table in ChangeDataCapture Database by executing the following TSQL Query:

Use ChangeDataCapture
Go
Create table Currency
(
CurrencyKey Int Identity(1,1) Primary Key NOT NULL,
CurrencyAlternateKey varchar(5)
) 



2. Once the Currency table is successfully created, you need to make sure that the SQL Server Agent Service is running. In order for the CDC to be successful the SQL Server Agent should be running.

3. Enable CDC for the table Currency by executing the below mentioned TSQL Query

Use ChangeDataCapture
Go
EXEC sp_cdc_enable_table  'dbo', 'Currency', @role_name = NULL, @supports_net_changes =1
Go



4. Execute the query below to check whether the table is enabled for CDC

Use ChangeDataCapture
Go
Select [name], is_tracked_by_cdc from sys.tables
GO

The value of 1 for the is_tracked_by_cdc column means that CDC is enabled for the table and the value of 0 for is_tracked_by_cdc column means that CDC is disabled.



5. Once you have enabled CDC for the Currency table, another table is created for keeping changed data and the information about the changes in the source table. The new table created will have cdc.dbo_Currency_CT name as shown. 

6. Next step will be to alter the Currency table to add the CurrencyName column:

Use ChangeDataCapture
Go
Alter table Currency add CurrencyName varchar(25)
Go

7. The DDL changes which have occurred to the Currency table can be viewed by executing the following TSQL Query:

Use ChangeDataCapture
Go
Select OBJECT_NAME(Source_Object_ID) As [Table Name], 
            OBJECT_NAME(Object_ID) As [CDC Table Name],
                DDL_Command As [DDL Command],
            DDL_LSN As [Log Sequence Number],
            DDL_Time As [DateModified]
From CDC.ddl_history
Go



Conclusion
The Change Data Capture feature helps DBA’s to enable CDC on a database table and keep track of all the Data Defination Language changes on a specific user table.