sql - CDC 是逐列而不是逐行更改，你能改进它吗？

Question

我正在编写一个返回 cdc 记录集的表值函数，而不是逐行返回更改的数据，我需要逐列输出它们。

例如，我有一个名为 auth.Account 的表，在字段电子邮件和密码上启用了 cdc。例如

EXEC sys.sp_cdc_enable_table @source_schema = N’auth’,
@source_name = N’Account’, @captured_column_list = N’
Email,
Password
@supports_net_changes = 1;

对，现在 cdc 已启用，我需要我的记录集如下所示：-

    -- =========================================
    -- Author:      Andrew Fenna
    -- Create date: 2013-08-15
    -- Description: Get Changed Auth Details TVF
    -- =========================================
    ALTER FUNCTION [auth].[ChangedAuthDetails] ( @FromLsn BINARY(10) )
    RETURNS @User TABLE
        (
          UserID INT ,
          CDC_OPERATION CHAR(1) ,
          LSN BINARY(10) ,
          CurrentEmail NVARCHAR(255) ,
          PreviousEmail NVARCHAR(255) ,
          CurrentPassword NVARCHAR(32) ,
          PreviousPassword NVARCHAR(32)
        )
    AS 
        BEGIN

            DECLARE @ToLsn BINARY(10)

            IF ( @FromLsn IS NULL ) 
                SELECT  @FromLsn = sys.fn_cdc_get_min_lsn(N'auth_account')
            ELSE 
                SELECT  @FromLsn = sys.fn_cdc_increment_lsn(@FromLsn)

            SELECT  @ToLsn = sys.fn_cdc_get_max_lsn()

            IF ( @FromLsn = sys.fn_cdc_increment_lsn(@ToLsn) ) 
                RETURN 

            -- Query for change data
            INSERT  INTO @User
                    SELECT  a.UserID ,
                            'U' AS [__$operation] ,
                            a.[__$start_lsn] ,
                            A.CurrentEmail ,
                            a.PreviousEmail ,
                            b.CurrentPassword ,
                            b.PreviousPassword
                    FROM    ( SELECT    Email.[__$start_lsn] ,
                                        Email.ID AS [UserID] ,
                                        Email.[3] AS [PreviousEmail] ,
                                        Email.[4] AS [CurrentEmail]
                              FROM      ( SELECT    [__$start_lsn] ,
                                                    ID ,
                                                    Email ,
                                                    [__$operation]
                                          FROM      cdc.fn_cdc_get_all_changes_auth_account(@FromLsn,
                                                                  @ToLsn, 'all update old')
                                          WHERE     [__$operation] IN ( 3, 4 )
                                        ) P PIVOT
                            ( MAX(Email) FOR [__$operation] IN ( [3], [4] ) ) AS Email
                            ) A
                            CROSS APPLY ( SELECT    [password].[__$start_lsn] ,
                                                    [Password].[3] AS [PreviousPassword] ,
                                                    [Password].[4] AS [CurrentPassword]
                                          FROM      ( SELECT    [__$start_lsn] ,
                                                                ID ,
                                                                [Password] ,
                                                                [__$operation]
                                                      FROM      cdc.fn_cdc_get_all_changes_auth_account(@FromLsn,
                                                                  @ToLsn, 'all update old')
                                                      WHERE     [__$operation] IN ( 3, 4 )
                                                    ) P PIVOT
                            ( MAX([Password]) FOR [__$operation] IN ( [3], [4] ) ) AS [Password]
                                        ) B
                    WHERE   A.__$start_lsn = B.__$start_lsn
                    UNION
                    SELECT  [ID] AS [UserID] ,
                            CASE __$operation
                              WHEN 1 THEN 'D'
                              WHEN 2 THEN 'I'
                              ELSE NULL
                            END AS CDC_OPERATION,
                            [__$start_lsn] ,
                            CASE [__$operation]
                              WHEN 1 THEN NULL
                              WHEN 2 THEN Email
                            END AS [CurrentEmail] ,
                            CASE [__$operation]
                              WHEN 1 THEN Email
                              WHEN 2 THEN NULL
                            END AS [PreviousEmail] ,
                            CASE [__$operation]
                              WHEN 1 THEN NULL
                              WHEN 2 THEN [Password]
                            END AS [CurrentPassword] ,
                            CASE [__$operation]
                              WHEN 1 THEN [Password]
                              WHEN 2 THEN NULL
                            END AS [PreviousPassword]
                    FROM      cdc.fn_cdc_get_all_changes_auth_account(@FromLsn,
                                                                  @ToLsn, 'all update old')
                    WHERE   [__$operation] < 3
            RETURN
        END

ID、CDC_OPERATION、LSN、CurrentEmail、PreviousEmail、CurrentPassword、PreviousPassword

到目前为止，这是我的解决方案，是的，我知道它有点混乱并且可以改进，关于如何改进它的任何想法？谢谢

原创博客在这里！