ApexSQL Log中的Redo Script跟原始SQL不一致問題

最近遇到一個誤更新數據的問題，使用ApexSQL Log作挖掘事務日誌的時候，發現ApexSQL Log生成的Redo Script跟原始SQL是有區別的。它們並非徹底一致的。只是邏輯上等價而已。以下所示，咱們作一個測試，以下所示，建立一個表後，並模擬忘記添加條件，出現誤刪除數據的狀況

 

SELECT * INTO KERRY_TEST FROM SYS.OBJECTS;

DELETE FROM KERRY_TEST

 

 

而後咱們用ApexSQL Log挖掘事務日誌，你會看到有不少對應的Delete記錄，並且對應的Redo Script跟原始SQL是不同的。以下所示，

 

 

 

 

下面是其中兩個Redo  Script（爲了方便查看，對腳本進行了格式化）

 

 

--DELETE (0003F73C:000065FC:000D) done at 2019-06-13 10:35:56.876 by xxx\xxxx in transaction 0000:0ADF73EA (Committed)

BEGIN TRANSACTION;

DELETE  FROM [dbo].[KERRY_TEST]

WHERE   /*** WARNING: WHERE CLAUSE FOR THIS STATEMENT WAS GENERATED FOR A TABLE WITH NO PRIMARY KEY AND NO CLUSTERED INDEX ***/

        [name] = N'sysfgfrag' COLLATE Chinese_PRC_CI_AS

        AND [object_id] = 19

        AND [principal_id] IS NULL

        AND [schema_id] = 4

        AND [parent_object_id] = 0

        AND [type] = N'S ' COLLATE Latin1_General_CI_AS_KS_WS

        AND [type_desc] = N'SYSTEM_TABLE' COLLATE Latin1_General_CI_AS_KS_WS

        AND [create_date] = '20160101 10:46:55.060'

        AND [modify_date] = '20160101 10:46:55.100'

        AND [is_ms_shipped] = 1

        AND [is_published] = 0

        AND [is_schema_published] = 0;

IF @@ROWCOUNT <= 1

    COMMIT TRANSACTION;

ELSE

    BEGIN

        ROLLBACK TRANSACTION;

            PRINT 'ERROR: STATEMENT AFFECTED MORE THAN ONE ROW. ALL THE CHANGES WERE ROLLED BACK.';

    END;

--DELETE (0003F73C:000065FC:000A) done at 2019-06-13 10:35:56.876 by xxx\xxx in transaction 0000:0ADF73EA (Committed)

BEGIN TRANSACTION;

DELETE  FROM [dbo].[KERRY_TEST]

WHERE   /*** WARNING: WHERE CLAUSE FOR THIS STATEMENT WAS GENERATED FOR A TABLE WITH NO PRIMARY KEY AND NO CLUSTERED INDEX ***/

        [name] = N'sysseobjvalues' COLLATE Chinese_PRC_CI_AS

        AND [object_id] = 9

        AND [principal_id] IS NULL

        AND [schema_id] = 4

        AND [parent_object_id] = 0

        AND [type] = N'S ' COLLATE Latin1_General_CI_AS_KS_WS

        AND [type_desc] = N'SYSTEM_TABLE' COLLATE Latin1_General_CI_AS_KS_WS

        AND [create_date] = '20160101 10:47:02.050'

        AND [modify_date] = '20160101 10:47:02.057'

        AND [is_ms_shipped] = 1

        AND [is_published] = 0

        AND [is_schema_published] = 0;

IF @@ROWCOUNT <= 1

    COMMIT TRANSACTION;

ELSE

    BEGIN

        ROLLBACK TRANSACTION;

            PRINT 'ERROR: STATEMENT AFFECTED MORE THAN ONE ROW. ALL THE CHANGES WERE ROLLED BACK.';

    END;

 

 

若是有彙集索引，你會看到沒有WHERE條件的UPDATE、DELETE操做都會生成不少個對應的Redo Script，對應的WHERE條件則是彙集索引字段。以下測試所示：

SELECT  *

INTO    KERRY_TEST2

FROM    sys.objects;

CREATE CLUSTERED INDEX PK_KERRY_TEST2 ON KERRY_TEST2(OBJECT_ID);

UPDATE  KERRY_TEST2

SET     NAME = 'KERRY';

DELETE  FROM KERRY_TEST2;

 

 

 

下面是對應的UPDATE、DELETE操做的redo script

--UPDATE (0003F73C:0000700A:001F) done at 2019-06-13 11:27:26.036 by xxx\xxx in transaction 0000:0ADF7404 (Committed)

BEGIN TRANSACTION; 

UPDATE  [dbo].[KERRY_TEST2]

SET     [name] = N'KERRY' COLLATE Chinese_PRC_CI_AS

WHERE   [object_id] = 3;

IF @@ROWCOUNT <= 1

    COMMIT TRANSACTION;

ELSE

    BEGIN

        ROLLBACK TRANSACTION;

            PRINT 'ERROR: STATEMENT AFFECTED MORE THAN ONE ROW. ALL THE CHANGES WERE ROLLED BACK.';

    END;

--    DELETE (0003F73C:00007482:00D9) done at 2019-06-13 11:27:35.406 by xxx\xxx in transaction 0000:0ADF7405 (Committed)

BEGIN TRANSACTION;

DELETE  FROM [dbo].[KERRY_TEST2]

WHERE   [object_id] = 836302139;

IF @@ROWCOUNT <= 1

    COMMIT TRANSACTION;

ELSE

    BEGIN

        ROLLBACK TRANSACTION;

            PRINT 'ERROR: STATEMENT AFFECTED MORE THAN ONE ROW. ALL THE CHANGES WERE ROLLED BACK.';

    END;

 

這裏只是簡單記錄一下這個事情，千萬不要覺得Redo Script跟原始SQL是徹底一致的。若是遇到這種問題，如何判斷呢？能夠查看Transaction ID，以及對應的Begin Time , End Time,以下所示，你會發現它們是一致的