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转 --- 恢复误删数据

时间:2016-10-12 00:28:59      阅读:405      评论:0      收藏:0      [点我收藏+]

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曾经想实现Log Explorer for SQL Server的功能,利用ldf里面的日志来还原误删除的数据

这里有一篇文章做到了,不过似乎不是所有的数据类型都支持

以下为译文:http://raresql.com/2011/10/22/how-to-recover-deleted-data-from-sql-sever/

 

在我使用SQLSERVER的这些年里面,大部分人都会问我一个问题:“能不能恢复被删除的数据??”

现在,从SQLSERVER2005 或以上版本能很容易能够恢复被删除的数据

(注意:这个脚本能恢复下面的数据类型的数据 而且兼容CS 排序规则)

  • image
  • text
  • uniqueidentifier
  • tinyint
  • smallint
  • int
  • smalldatetime
  • real
  • money
  • datetime
  • float
  • sql_variant
  • ntext
  • bit
  • decimal
  • numeric
  • smallmoney
  • bigint
  • varbinary
  • varchar
  • binary
  • char
  • timestamp
  • nvarchar
  • nchar
  • xml
  • sysname

 

 

让我来用demo来解释一下我是怎么做到的

USE master
GO--创建数据库CREATEDATABASE test
GOUSE[test]GO--创建表CREATETABLE[dbo].[aa](
    [id][int]IDENTITY(1,1) NOTNULL,
    [NAME][nvarchar](200) NULL
) ON[PRIMARY]GO--插入测试数据INSERT[dbo].[aa]
        ( [NAME] )
SELECT‘你好‘GO--删除数据Deletefrom aa
Go--验证数据是否已经删除Select*from aa
Go

 

现在你需要创建一个存储过程来恢复你的数据

技术分享
-- Script Name: Recover_Deleted_Data_Proc
-- Script Type : Recovery Procedure 
-- Develop By: Muhammad Imran
-- Date Created: 15 Oct 2011
-- Modify Date: 22 Aug 2012
-- Version    : 3.1
-- Notes : Included BLOB data types for recovery.& Compatibile with Default , CS collation , Arabic_CI_AS.CREATEPROCEDURE Recover_Deleted_Data_Proc
    @Database_NameNVARCHAR(MAX) ,
    @SchemaName_n_TableNameNVARCHAR(MAX) ,
    @Date_FromDATETIME=‘1900/01/01‘ ,
    @Date_ToDATETIME=‘9999/12/31‘ASDECLARE@RowLogContentsVARBINARY(8000)
    DECLARE@TransactionIDNVARCHAR(MAX)
    DECLARE@AllocUnitIDBIGINTDECLARE@AllocUnitNameNVARCHAR(MAX)
    DECLARE@SQLNVARCHAR(MAX)
    DECLARE@Compatibility_LevelINTSELECT@Compatibility_Level= dtb.compatibility_level
    FROM    master.sys.databases AS dtb
    WHERE   dtb.name =@Database_NameIFISNULL(@Compatibility_Level, 0) <=80BEGINRAISERROR(‘The compatibility level should be equal to or greater SQL SERVER 2005 (90)‘,16,1)
            RETURNENDIF ( SELECTCOUNT(*)
         FROM   INFORMATION_SCHEMA.TABLES
         WHERE[TABLE_SCHEMA]+‘.‘+[TABLE_NAME]=@SchemaName_n_TableName
       ) =0BEGINRAISERROR(‘Could not found the table in the defined database‘,16,1)
            RETURNENDDECLARE@bitTableTABLE
        (
          [ID]INT ,
          [Bitvalue]INT
        )
--Create table to set the bit position of one byte.INSERTINTO@bitTableSELECT0 ,
                    2UNIONALLSELECT1 ,
                    2UNIONALLSELECT2 ,
                    4UNIONALLSELECT3 ,
                    8UNIONALLSELECT4 ,
                    16UNIONALLSELECT5 ,
                    32UNIONALLSELECT6 ,
                    64UNIONALLSELECT7 ,
                    128--Create table to collect the row data.DECLARE@DeletedRecordsTABLE
        (
          [Row ID]INTIDENTITY(1, 1) ,
          [RowLogContents]VARBINARY(8000) ,
          [AllocUnitID]BIGINT ,
          [Transaction ID]NVARCHAR(MAX) ,
          [FixedLengthData]SMALLINT ,
          [TotalNoOfCols]SMALLINT ,
          [NullBitMapLength]SMALLINT ,
          [NullBytes]VARBINARY(8000) ,
          [TotalNoofVarCols]SMALLINT ,
          [ColumnOffsetArray]VARBINARY(8000) ,
          [VarColumnStart]SMALLINT ,
          [Slot ID]INT ,
          [NullBitMap]VARCHAR(MAX)
        )
--Create a common table expression to get all the row data plus how many bytes we have for each row.;
    WITH    RowData
              AS ( SELECT[RowLog Contents 0]AS[RowLogContents] ,
                            [AllocUnitID]AS[AllocUnitID] ,
                            [Transaction ID]AS[Transaction ID]--[Fixed Length Data] = Substring (RowLog content 0, Status Bit A+ Status Bit B + 1,2 bytes)                            ,
                            CONVERT(SMALLINT, CONVERT(BINARY(2), REVERSE(SUBSTRING([RowLog Contents 0],
                                                              2+1, 2)))) AS[FixedLengthData]--@FixedLengthData-- [TotalnoOfCols] =  Substring (RowLog content 0, [Fixed Length Data] + 1,2 bytes)                            ,
                            CONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([RowLog Contents 0],
                                                              CONVERT(SMALLINT, CONVERT(BINARY(2), REVERSE(SUBSTRING([RowLog Contents 0],
                                                              2+1, 2)))) +1,
                                                              2)))) AS[TotalNoOfCols]--[NullBitMapLength]=ceiling([Total No of Columns] /8.0)                            ,
                            CONVERT(INT, CEILING(CONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([RowLog Contents 0],
                                                              CONVERT(SMALLINT, CONVERT(BINARY(2), REVERSE(SUBSTRING([RowLog Contents 0],
                                                              2+1, 2)))) +1,
                                                              2)))) /8.0)) AS[NullBitMapLength]--[Null Bytes] = Substring (RowLog content 0, Status Bit A+ Status Bit B + [Fixed Length Data] +1, [NullBitMapLength] )                            ,
                            SUBSTRING([RowLog Contents 0],
                                      CONVERT(SMALLINT, CONVERT(BINARY(2), REVERSE(SUBSTRING([RowLog Contents 0],
                                                              2+1, 2)))) +3,
                                      CONVERT(INT, CEILING(CONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([RowLog Contents 0],
                                                              CONVERT(SMALLINT, CONVERT(BINARY(2), REVERSE(SUBSTRING([RowLog Contents 0],
                                                              2+1, 2)))) +1,
                                                              2)))) /8.0))) AS[NullBytes]--[TotalNoofVarCols] = Substring (RowLog content 0, Status Bit A+ Status Bit B + [Fixed Length Data] +1, [Null Bitmap length] + 2 )                            ,
                            ( CASEWHENSUBSTRING([RowLog Contents 0], 1, 1) IN (
                                        0x10, 0x30, 0x70 )
                                   THENCONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([RowLog Contents 0],
                                                              CONVERT(SMALLINT, CONVERT(BINARY(2), REVERSE(SUBSTRING([RowLog Contents 0],
                                                              2+1, 2)))) +3+CONVERT(INT, CEILING(CONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([RowLog Contents 0],
                                                              CONVERT(SMALLINT, CONVERT(BINARY(2), REVERSE(SUBSTRING([RowLog Contents 0],
                                                              2+1, 2)))) +1,
                                                              2)))) /8.0)), 2))))
                                   ELSENULLEND ) AS[TotalNoofVarCols]--[ColumnOffsetArray]= Substring (RowLog content 0, Status Bit A+ Status Bit B + [Fixed Length Data] +1, [Null Bitmap length] + 2 , [TotalNoofVarCols]*2 )                            ,
                            ( CASEWHENSUBSTRING([RowLog Contents 0], 1, 1) IN (
                                        0x10, 0x30, 0x70 )
                                   THENSUBSTRING([RowLog Contents 0],
                                                  CONVERT(SMALLINT, CONVERT(BINARY(2), REVERSE(SUBSTRING([RowLog Contents 0],
                                                              2+1, 2)))) +3+CONVERT(INT, CEILING(CONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([RowLog Contents 0],
                                                              CONVERT(SMALLINT, CONVERT(BINARY(2), REVERSE(SUBSTRING([RowLog Contents 0],
                                                              2+1, 2)))) +1,
                                                              2)))) /8.0))
                                                  +2,
                                                  ( CASEWHENSUBSTRING([RowLog Contents 0],
                                                              1, 1) IN ( 0x10,
                                                              0x30, 0x70 )
                                                         THENCONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([RowLog Contents 0],
                                                              CONVERT(SMALLINT, CONVERT(BINARY(2), REVERSE(SUBSTRING([RowLog Contents 0],
                                                              2+1, 2)))) +3+CONVERT(INT, CEILING(CONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([RowLog Contents 0],
                                                              CONVERT(SMALLINT, CONVERT(BINARY(2), REVERSE(SUBSTRING([RowLog Contents 0],
                                                              2+1, 2)))) +1,
                                                              2)))) /8.0)), 2))))
                                                         ELSENULLEND ) *2)
                                   ELSENULLEND ) AS[ColumnOffsetArray]--  Variable column Start = Status Bit A+ Status Bit B + [Fixed Length Data] + [Null Bitmap length] + 2+([TotalNoofVarCols]*2)                            ,
                            CASEWHENSUBSTRING([RowLog Contents 0], 1, 1) IN (
                                      0x10, 0x30, 0x70 )
                                 THEN ( CONVERT(SMALLINT, CONVERT(BINARY(2), REVERSE(SUBSTRING([RowLog Contents 0],
                                                              2+1, 2)))) +4+CONVERT(INT, CEILING(CONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([RowLog Contents 0],
                                                              CONVERT(SMALLINT, CONVERT(BINARY(2), REVERSE(SUBSTRING([RowLog Contents 0],
                                                              2+1, 2)))) +1,
                                                              2)))) /8.0))
                                        + ( ( CASEWHENSUBSTRING([RowLog Contents 0],
                                                              1, 1) IN ( 0x10,
                                                              0x30, 0x70 )
                                                   THENCONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([RowLog Contents 0],
                                                              CONVERT(SMALLINT, CONVERT(BINARY(2), REVERSE(SUBSTRING([RowLog Contents 0],
                                                              2+1, 2)))) +3+CONVERT(INT, CEILING(CONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([RowLog Contents 0],
                                                              CONVERT(SMALLINT, CONVERT(BINARY(2), REVERSE(SUBSTRING([RowLog Contents 0],
                                                              2+1, 2)))) +1,
                                                              2)))) /8.0)), 2))))
                                                   ELSENULLEND ) *2 ) )
                                 ELSENULLENDAS[VarColumnStart] ,
                            [Slot ID]FROM     sys.fn_dblog(NULL, NULL)
                   WHERE    AllocUnitId IN (
                            SELECT[Allocation_unit_id]FROM    sys.allocation_units allocunits
                                    INNERJOIN sys.partitions partitions ON ( allocunits.type IN (
                                                              1, 3 )
                                                              AND partitions.hobt_id = allocunits.container_id
                                                              )
                                                              OR ( allocunits.type =2AND partitions.partition_id = allocunits.container_id
                                                              )
                            WHEREobject_id=OBJECT_ID(‘‘+@SchemaName_n_TableName+‘‘) )
                            AND Context IN ( ‘LCX_MARK_AS_GHOST‘, ‘LCX_HEAP‘ )
                            AND Operation IN ( ‘LOP_DELETE_ROWS‘ )
                            ANDSUBSTRING([RowLog Contents 0], 1, 1) IN ( 0x10,
                                                              0x30, 0x70 )
 
/*Use this subquery to filter the date*/AND[TRANSACTION ID]IN (
                            SELECTDISTINCT[TRANSACTION ID]FROM    sys.fn_dblog(NULL, NULL)
                            WHERE   Context IN ( ‘LCX_NULL‘ )
                                    AND Operation IN ( ‘LOP_BEGIN_XACT‘ )
                                    AND[Transaction Name]IN ( ‘DELETE‘,
                                                              ‘user_transaction‘ )
                                    ANDCONVERT(NVARCHAR(11), [Begin Time]) BETWEEN@Date_FromAND@Date_To )
                 ),
 
--Use this technique to repeate the row till the no of bytes of the row.            N1 ( n )
              AS ( SELECT1UNIONALLSELECT1
                 ),
            N2 ( n )
              AS ( SELECT1FROM     N1 AS X ,
                            N1 AS Y
                 ),
            N3 ( n )
              AS ( SELECT1FROM     N2 AS X ,
                            N2 AS Y
                 ),
            N4 ( n )
              AS ( SELECT   ROW_NUMBER() OVER ( ORDERBY X.n )
                   FROM     N3 AS X ,
                            N3 AS Y
                 )
        INSERTINTO@DeletedRecordsSELECT  RowLogContents ,
                        [AllocUnitID] ,
                        [Transaction ID] ,
                        [FixedLengthData] ,
                        [TotalNoOfCols] ,
                        [NullBitMapLength] ,
                        [NullBytes] ,
                        [TotalNoofVarCols] ,
                        [ColumnOffsetArray] ,
                        [VarColumnStart] ,
                        [Slot ID]---Get the Null value against each column (1 means null zero means not null)                        ,
                        [NullBitMap]= ( REPLACE(STUFF(( SELECT‘,‘+ ( CASEWHEN[ID]=0THENCONVERT(NVARCHAR(1), ( SUBSTRING(NullBytes,
                                                              n, 1) %2 ))
                                                              ELSECONVERT(NVARCHAR(1), ( ( SUBSTRING(NullBytes,
                                                              n, 1)
                                                              /[Bitvalue] )
                                                              %2 ))
                                                              END ) --as [nullBitMap]FROM N4 AS Nums
                                                              JOIN RowData AS C ON n <= NullBitMapLength
                                                              CROSSJOIN@bitTableWHERE
                                                              C.[RowLogContents]= D.[RowLogContents]ORDERBY[RowLogContents] ,
                                                              n ASCFOR
                                                         XML PATH(‘‘)
                                                       ), 1, 1, ‘‘), ‘,‘, ‘‘) )
                FROM    RowData D
 
    IF ( SELECTCOUNT(*)
         FROM@DeletedRecords
       ) =0BEGINRAISERROR(‘There is no data in the log as per the search criteria‘,16,1)
            RETURNENDDECLARE@ColumnNameAndDataTABLE
        (
          [Row ID]INT ,
          [Rowlogcontents]VARBINARY(MAX) ,
          [NAME] SYSNAME ,
          [nullbit]SMALLINT ,
          [leaf_offset]SMALLINT ,
          [length]SMALLINT ,
          [system_type_id]TINYINT ,
          [bitpos]TINYINT ,
          [xprec]TINYINT ,
          [xscale]TINYINT ,
          [is_null]INT ,
          [Column value Size]INT ,
          [Column Length]INT ,
          [hex_Value]VARBINARY(MAX) ,
          [Slot ID]INT ,
          [Update]INT
        )
 
--Create common table expression and join it with the rowdata table
-- to get each column details
/*This part is for variable data columns*/--@RowLogContents, 
--(col.columnOffValue - col.columnLength) + 1,
--col.columnLength
--)INSERTINTO@ColumnNameAndDataSELECT[Row ID] ,
                    Rowlogcontents ,
                    NAME ,
                    cols.leaf_null_bit AS nullbit ,
                    leaf_offset ,
                    ISNULL(syscolumns.length, cols.max_length) AS[length] ,
                    cols.system_type_id ,
                    cols.leaf_bit_position AS bitpos ,
                    ISNULL(syscolumns.xprec, cols.precision) AS xprec ,
                    ISNULL(syscolumns.xscale, cols.scale) AS xscale ,
                    SUBSTRING([nullBitMap], cols.leaf_null_bit, 1) AS is_null ,
                    ( CASEWHEN leaf_offset <1ANDSUBSTRING([nullBitMap], cols.leaf_null_bit,
                                              1) =0THEN ( CASEWHENCONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* leaf_offset
                                                              *-1 ) -1, 2)))) >30000THENCONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* leaf_offset
                                                              *-1 ) -1, 2))))
                                            -POWER(2, 15)
                                       ELSECONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* leaf_offset
                                                              *-1 ) -1, 2))))
                                  END )
                      END ) AS[Column value Size] ,
                    ( CASEWHEN leaf_offset <1ANDSUBSTRING([nullBitMap], cols.leaf_null_bit,
                                              1) =0THEN ( CASEWHENCONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* leaf_offset
                                                              *-1 ) -1, 2)))) >30000ANDISNULL(NULLIF(CONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* ( ( leaf_offset
                                                              *-1 ) -1 ) )
                                                              -1, 2)))), 0),
                                                       [varColumnStart]) <30000THEN ( CASEWHEN[System_type_id]IN (
                                                        35, 34, 99 ) THEN16ELSE24END )
                                       WHENCONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* leaf_offset
                                                              *-1 ) -1, 2)))) >30000ANDISNULL(NULLIF(CONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* ( ( leaf_offset
                                                              *-1 ) -1 ) )
                                                              -1, 2)))), 0),
                                                       [varColumnStart]) >30000THEN ( CASEWHEN[System_type_id]IN (
                                                        35, 34, 99 ) THEN16ELSE24END ) --24 WHENCONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* leaf_offset
                                                              *-1 ) -1, 2)))) <30000ANDISNULL(NULLIF(CONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* ( ( leaf_offset
                                                              *-1 ) -1 ) )
                                                              -1, 2)))), 0),
                                                       [varColumnStart]) <30000THEN ( CONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* leaf_offset
                                                              *-1 ) -1, 2))))
                                              -ISNULL(NULLIF(CONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* ( ( leaf_offset
                                                              *-1 ) -1 ) )
                                                              -1, 2)))), 0),
                                                       [varColumnStart]) )
                                       WHENCONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* leaf_offset
                                                              *-1 ) -1, 2)))) <30000ANDISNULL(NULLIF(CONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* ( ( leaf_offset
                                                              *-1 ) -1 ) )
                                                              -1, 2)))), 0),
                                                       [varColumnStart]) >30000THENPOWER(2, 15)
                                            +CONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* leaf_offset
                                                              *-1 ) -1, 2))))
                                            -ISNULL(NULLIF(CONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* ( ( leaf_offset
                                                              *-1 ) -1 ) )
                                                              -1, 2)))), 0),
                                                     [varColumnStart])
                                  END )
                      END ) AS[Column Length] ,
                    ( CASEWHENSUBSTRING([nullBitMap], cols.leaf_null_bit, 1) =1THENNULLELSESUBSTRING(Rowlogcontents,
                                          ( ( CASEWHENCONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* leaf_offset
                                                              *-1 ) -1, 2)))) >30000THENCONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* leaf_offset
                                                              *-1 ) -1, 2))))
                                                        -POWER(2, 15)
                                                   ELSECONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* leaf_offset
                                                              *-1 ) -1, 2))))
                                              END )
                                            - ( CASEWHENCONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* leaf_offset
                                                              *-1 ) -1, 2)))) >30000ANDISNULL(NULLIF(CONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* ( ( leaf_offset
                                                              *-1 ) -1 ) )
                                                              -1, 2)))), 0),
                                                              [varColumnStart]) <30000THEN ( CASEWHEN[System_type_id]IN (
                                                              35, 34, 99 )
                                                              THEN16ELSE24END ) --24 WHENCONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* leaf_offset
                                                              *-1 ) -1, 2)))) >30000ANDISNULL(NULLIF(CONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* ( ( leaf_offset
                                                              *-1 ) -1 ) )
                                                              -1, 2)))), 0),
                                                              [varColumnStart]) >30000THEN ( CASEWHEN[System_type_id]IN (
                                                              35, 34, 99 )
                                                              THEN16ELSE24END ) --24 WHENCONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* leaf_offset
                                                              *-1 ) -1, 2)))) <30000ANDISNULL(NULLIF(CONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* ( ( leaf_offset
                                                              *-1 ) -1 ) )
                                                              -1, 2)))), 0),
                                                              [varColumnStart]) <30000THENCONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* leaf_offset
                                                              *-1 ) -1, 2))))
                                                          -ISNULL(NULLIF(CONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* ( ( leaf_offset
                                                              *-1 ) -1 ) )
                                                              -1, 2)))), 0),
                                                              [varColumnStart])
                                                     WHENCONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* leaf_offset
                                                              *-1 ) -1, 2)))) <30000ANDISNULL(NULLIF(CONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* ( ( leaf_offset
                                                              *-1 ) -1 ) )
                                                              -1, 2)))), 0),
                                                              [varColumnStart]) >30000THENPOWER(2, 15)
                                                          +CONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* leaf_offset
                                                              *-1 ) -1, 2))))
                                                          -ISNULL(NULLIF(CONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* ( ( leaf_offset
                                                              *-1 ) -1 ) )
                                                              -1, 2)))), 0),
                                                              [varColumnStart])
                                                END ) ) +1,
                                          ( CASEWHENCONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* leaf_offset
                                                              *-1 ) -1, 2)))) >30000ANDISNULL(NULLIF(CONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* ( ( leaf_offset
                                                              *-1 ) -1 ) )
                                                              -1, 2)))), 0),
                                                              [varColumnStart]) <30000THEN ( CASEWHEN[System_type_id]IN (
                                                              35, 34, 99 )
                                                             THEN16ELSE24END ) --24 WHENCONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* leaf_offset
                                                              *-1 ) -1, 2)))) >30000ANDISNULL(NULLIF(CONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* ( ( leaf_offset
                                                              *-1 ) -1 ) )
                                                              -1, 2)))), 0),
                                                              [varColumnStart]) >30000THEN ( CASEWHEN[System_type_id]IN (
                                                              35, 34, 99 )
                                                             THEN16ELSE24END ) --24 WHENCONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* leaf_offset
                                                              *-1 ) -1, 2)))) <30000ANDISNULL(NULLIF(CONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* ( ( leaf_offset
                                                              *-1 ) -1 ) )
                                                              -1, 2)))), 0),
                                                              [varColumnStart]) <30000THENABS(CONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* leaf_offset
                                                              *-1 ) -1, 2))))
                                                          -ISNULL(NULLIF(CONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* ( ( leaf_offset
                                                              *-1 ) -1 ) )
                                                              -1, 2)))), 0),
                                                              [varColumnStart]))
                                                 WHENCONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* leaf_offset
                                                              *-1 ) -1, 2)))) <30000ANDISNULL(NULLIF(CONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* ( ( leaf_offset
                                                              *-1 ) -1 ) )
                                                              -1, 2)))), 0),
                                                              [varColumnStart]) >30000THENPOWER(2, 15)
                                                      +CONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* leaf_offset
                                                              *-1 ) -1, 2))))
                                                      -ISNULL(NULLIF(CONVERT(INT, CONVERT(BINARY(2), REVERSE(SUBSTRING([ColumnOffsetArray],
                                                              ( 2* ( ( leaf_offset
                                                              *-1 ) -1 ) )
                                                              -1, 2)))), 0),
                                                              [varColumnStart])
                                            END ))
                      END ) AS hex_Value ,
                    [Slot ID] ,
                    0FROM@DeletedRecords A
                    INNERJOIN sys.allocation_units allocunits ON A.[AllocUnitId]= allocunits.[Allocation_Unit_Id]INNERJOIN sys.partitions partitions ON ( allocunits.type IN (
                                                              1, 3 )
                                                              AND partitions.hobt_id = allocunits.container_id
                                                            )
                                                            OR ( allocunits.type =2AND partitions.partition_id = allocunits.container_id
                                                              )
                    INNERJOIN sys.system_internals_partition_columns cols ON cols.partition_id = partitions.partition_id
                    LEFTOUTERJOIN syscolumns ON syscolumns.id = partitions.object_idAND syscolumns.colid = cols.partition_column_id
            WHERE   leaf_offset <0UNION/*This part is for fixed data columns*/SELECT[Row ID] ,
                    Rowlogcontents ,
                    NAME ,
                    cols.leaf_null_bit AS nullbit ,
                    leaf_offset ,
                    ISNULL(syscolumns.length, cols.max_length) AS[length] ,
                    cols.system_type_id ,
                    cols.leaf_bit_position AS bitpos ,
                    ISNULL(syscolumns.xprec, cols.precision) AS xprec ,
                    ISNULL(syscolumns.xscale, cols.scale) AS xscale ,
                    SUBSTRING([nullBitMap], cols.leaf_null_bit, 1) AS is_null ,
                    ( SELECTTOP1ISNULL(SUM(CASEWHEN C.leaf_offset >1THEN max_length
                                                ELSE0END), 0)
                      FROM      sys.system_internals_partition_columns C
                      WHERE     cols.partition_id = C.partition_id
                                AND C.leaf_null_bit < cols.leaf_null_bit
                    ) +5AS[Column value Size] ,
                    syscolumns.length AS[Column Length] ,
                    CASEWHENSUBSTRING([nullBitMap], cols.leaf_null_bit, 1) =1THENNULLELSESUBSTRING(Rowlogcontents,
                                        ( SELECTTOP1ISNULL(SUM(CASEWHEN C.leaf_offset >1AND C.leaf_bit_position =0THEN max_length
                                                              ELSE0END), 0)
                                          FROM      sys.system_internals_partition_columns C
                                          WHERE     cols.partition_id = C.partition_id
                                                    AND C.leaf_null_bit < cols.leaf_null_bit
                                        ) +5, syscolumns.length)
                    ENDAS hex_Value ,
                    [Slot ID] ,
                    0FROM@DeletedRecords A
                    INNERJOIN sys.allocation_units allocunits ON A.[AllocUnitId]= allocunits.[Allocation_Unit_Id]INNERJOIN sys.partitions partitions ON ( allocunits.type IN (
                                                              1, 3 )
                                                              AND partitions.hobt_id = allocunits.container_id
                                                            )
                                                            OR ( allocunits.type =2AND partitions.partition_id = allocunits.container_id
                                                              )
                    INNERJOIN sys.system_internals_partition_columns cols ON cols.partition_id = partitions.partition_id
                    LEFTOUTERJOIN syscolumns ON syscolumns.id = partitions.object_idAND syscolumns.colid = cols.partition_column_id
            WHERE   leaf_offset >0ORDERBY nullbit
 
    DECLARE@BitColumnByteASINTSELECT@BitColumnByte=CONVERT(INT, CEILING(COUNT(*) /8.0))
    FROM@ColumnNameAndDataWHERE[System_Type_id]=104;
    WITH    N1 ( n )
              AS ( SELECT1UNIONALLSELECT1
                 ),
            N2 ( n )
              AS ( SELECT1FROM     N1 AS X ,
                            N1 AS Y
                 ),
            N3 ( n )
              AS ( SELECT1FROM     N2 AS X ,
                            N2 AS Y
                 ),
            N4 ( n )
              AS ( SELECT   ROW_NUMBER() OVER ( ORDERBY X.n )
                   FROM     N3 AS X ,
                            N3 AS Y
                 ),
            CTE
              AS ( SELECT   RowLogContents ,
                            [nullbit] ,
                            [BitMap]=CONVERT(VARBINARY(1), CONVERT(INT, SUBSTRING(( REPLACE(STUFF(( SELECT‘,‘+ ( CASEWHEN[ID]=0THENCONVERT(NVARCHAR(1), ( SUBSTRING(hex_Value,
                                                              n, 1) %2 ))
                                                              ELSECONVERT(NVARCHAR(1), ( ( SUBSTRING(hex_Value,
                                                              n, 1)
                                                              /[Bitvalue] )
                                                              %2 ))
                                                              END ) --as [nullBitMap]FROM
                                                              N4 AS Nums
                                                              JOIN@ColumnNameAndDataAS C ON n <=@BitColumnByteAND[System_Type_id]=104AND bitpos =0CROSSJOIN@bitTableWHERE
                                                              C.[RowLogContents]= D.[RowLogContents]ORDERBY[RowLogContents] ,
                                                              n ASCFOR
                                                              XML
                                                              PATH(‘‘)
                                                              ), 1, 1, ‘‘),
                                                              ‘,‘, ‘‘) ),
                                                              bitpos +1, 1)))
                   FROM@ColumnNameAndData D
                   WHERE[System_Type_id]=104
                 )
        UPDATE  A
        SET[hex_Value]=[BitMap]FROM@ColumnNameAndData A
                INNERJOIN CTE B ON A.[RowLogContents]= B.[RowLogContents]AND A.[nullbit]= B.[nullbit]/**************Check for BLOB DATA TYPES******************************/DECLARE@FileidINTDECLARE@PageidINTDECLARE@SlotidINTDECLARE@CurrentLSNINTDECLARE@LinkIDINTDECLARE@ContextVARCHAR(50)
    DECLARE@ConsolidatedPageIDVARCHAR(MAX)
    DECLARE@LCX_TEXT_MIXVARBINARY(MAX)
 
    DECLARE@temppagedataTABLE
        (
          [ParentObject] SYSNAME ,
          [Object] SYSNAME ,
          [Field] SYSNAME ,
          [Value] SYSNAME
        )
 
    DECLARE@pagedataTABLE
        (
          [Page ID] SYSNAME ,
          [File IDS]INT ,
          [Page IDS]INT ,
          [AllocUnitId]BIGINT ,
          [ParentObject] SYSNAME ,
          [Object] SYSNAME ,
          [Field] SYSNAME ,
          [Value] SYSNAME
        )
 
    DECLARE@ModifiedRawDataTABLE
        (
          [ID]INTIDENTITY(1, 1) ,
          [PAGE ID]VARCHAR(MAX) ,
          [FILE IDS]INT ,
          [PAGE IDS]INT ,
          [Slot ID]INT ,
          [AllocUnitId]BIGINT ,
          [RowLog Contents 0_var]VARCHAR(MAX) ,
          [RowLog Length]VARCHAR(50) ,
          [RowLog Len]INT ,
          [RowLog Contents 0]VARBINARY(MAX) ,
          [Link ID]INTDEFAULT ( 0 ) ,
          [Update]INT
        )
 
    DECLARE Page_Data_Cursor CURSORFOR/*We need to filter LOP_MODIFY_ROW,LOP_MODIFY_COLUMNS from log for deleted records of BLOB data type& Get its Slot No, Page ID & AllocUnit ID*/SELECTLTRIM(RTRIM(REPLACE([Description], ‘Deallocated‘, ‘‘))) AS[PAGE ID] ,
                    [Slot ID] ,
                    [AllocUnitId] ,
                    NULLAS[RowLog Contents 0] ,
                    NULLAS[RowLog Contents 0] ,
                    Context
            FROM    sys.fn_dblog(NULL, NULL)
            WHERE   AllocUnitId IN (
                    SELECT[Allocation_unit_id]FROM    sys.allocation_units allocunits
                            INNERJOIN sys.partitions partitions ON ( allocunits.type IN (
                                                              1, 3 )
                                                              AND partitions.hobt_id = allocunits.container_id
                                                              )
                                                              OR ( allocunits.type =2AND partitions.partition_id = allocunits.container_id
                                                              )
                    WHEREobject_id=OBJECT_ID(‘‘+@SchemaName_n_TableName+‘‘) )
                    AND Operation IN ( ‘LOP_MODIFY_ROW‘ )
                    AND[Context]IN ( ‘LCX_PFS‘ )
                    AND Description LIKE‘%Deallocated%‘/*Use this subquery to filter the date*/AND[TRANSACTION ID]IN (
                    SELECTDISTINCT[TRANSACTION ID]FROM    sys.fn_dblog(NULL, NULL)
                    WHERE   Context IN ( ‘LCX_NULL‘ )
                            AND Operation IN ( ‘LOP_BEGIN_XACT‘ )
                            AND[Transaction Name]=‘DELETE‘ANDCONVERT(NVARCHAR(11), [Begin Time]) BETWEEN@Date_FromAND@Date_To )
            GROUPBY[Description] ,
                    [Slot ID] ,
                    [AllocUnitId] ,
                    Context
            UNIONSELECT[PAGE ID] ,
                    [Slot ID] ,
                    [AllocUnitId] ,
                    SUBSTRING([RowLog Contents 0], 15,
                              LEN([RowLog Contents 0])) AS[RowLog Contents 0] ,
                    CONVERT(INT, SUBSTRING([RowLog Contents 0], 7, 2)) ,
                    Context --,CAST(RIGHT([Current LSN],4) AS INT) AS [Current LSN]FROM    sys.fn_dblog(NULL, NULL)
            WHERE   AllocUnitId IN (
                    SELECT[Allocation_unit_id]FROM    sys.allocation_units allocunits
                            INNERJOIN sys.partitions partitions ON ( allocunits.type IN (
                                                              1, 3 )
                                                              AND partitions.hobt_id = allocunits.container_id
                                                              )
                                                              OR ( allocunits.type =2AND partitions.partition_id = allocunits.container_id
                                                              )
                    WHEREobject_id=OBJECT_ID(‘‘+@SchemaName_n_TableName+‘‘) )
                    AND Context IN ( ‘LCX_TEXT_MIX‘ )
                    AND Operation IN ( ‘LOP_DELETE_ROWS‘ ) 
            /*Use this subquery to filter the date*/AND[TRANSACTION ID]IN (
                    SELECTDISTINCT[TRANSACTION ID]FROM    sys.fn_dblog(NULL, NULL)
                    WHERE   Context IN ( ‘LCX_NULL‘ )
                            AND Operation IN ( ‘LOP_BEGIN_XACT‘ )
                            AND[Transaction Name]=‘DELETE‘ANDCONVERT(NVARCHAR(11), [Begin Time]) BETWEEN@Date_FromAND@Date_To )
                         
            /****************************************/OPEN Page_Data_Cursor
 
    FETCHNEXTFROM Page_Data_Cursor INTO@ConsolidatedPageID, @Slotid,
        @AllocUnitID, @LCX_TEXT_MIX, @LinkID, @ContextWHILE@@FETCH_STATUS=0BEGINDECLARE@hex_pageidASVARCHAR(MAX)
            /*Page ID contains File Number and page number It looks like 0001:00000130.
              In this example 0001 is file Number &  00000130 is Page Number & These numbers are in Hex format*/SET@Fileid=SUBSTRING(@ConsolidatedPageID, 0,
                                    CHARINDEX(‘:‘, @ConsolidatedPageID)) -- Seperate File ID from Page IDSET@hex_pageid=‘0x‘+SUBSTRING(@ConsolidatedPageID,
                                               CHARINDEX(‘:‘,
                                                         @ConsolidatedPageID)
                                               +1, LEN(@ConsolidatedPageID))  ---Seperate the page IDSELECT@Pageid=CONVERT(INT, CAST(‘‘AS XML).value(‘xs:hexBinary(substring(sql:variable("@hex_pageid"),sql:column("t.pos")) )‘,
                                                              ‘varbinary(max)‘)) -- Convert Page ID from hex to integerFROM    ( SELECTCASESUBSTRING(@hex_pageid, 1, 2)
                                  WHEN‘0x‘THEN3ELSE0END
                    ) AS t ( pos ) 
             
            IF@Context=‘LCX_PFS‘BEGINDELETE@temppagedataINSERTINTO@temppagedataEXEC
                                ( ‘DBCC PAGE(‘+@DataBase_Name+‘, ‘+@fileid+‘, ‘+@pageid+‘, 1) with tableresults,no_infomsgs;‘
                                ); 
                    INSERTINTO@pagedataSELECT@ConsolidatedPageID ,
                                    @fileid ,
                                    @pageid ,
                                    @AllocUnitID ,
                                    [ParentObject] ,
                                    [Object] ,
                                    [Field] ,
                                    [Value]FROM@temppagedataENDELSEIF@Context=‘LCX_TEXT_MIX‘BEGININSERTINTO@ModifiedRawDataSELECT@ConsolidatedPageID ,
                                        @fileid ,
                                        @pageid ,
                                        @Slotid ,
                                        @AllocUnitID ,
                                        NULL ,
                                        0 ,
                                        CONVERT(INT, CONVERT(VARBINARY, REVERSE(SUBSTRING(@LCX_TEXT_MIX,
                                                              11, 2)))) ,
                                        @LCX_TEXT_MIX ,
                                        @LinkID ,
                                        0ENDFETCHNEXTFROM Page_Data_Cursor INTO@ConsolidatedPageID, @Slotid,
                @AllocUnitID, @LCX_TEXT_MIX, @LinkID, @ContextENDCLOSE Page_Data_Cursor
    DEALLOCATE Page_Data_Cursor
 
    DECLARE@NewhexstringVARCHAR(MAX);
 
    --The data is in multiple rows in the page, so we need to convert it into one row as a single hex value.--This hex value is in string formatINSERTINTO@ModifiedRawData
            ( [PAGE ID] ,
              [FILE IDS] ,
              [PAGE IDS] ,
              [Slot ID] ,
              [AllocUnitId] ,
              [RowLog Contents 0_var] ,
              [RowLog Length]
            )
            SELECT[Page ID] ,
                    [FILE IDS] ,
                    [PAGE IDS] ,
                    SUBSTRING([ParentObject],
                              CHARINDEX(‘Slot‘, [ParentObject]) +4,
                              ( CHARINDEX(‘Offset‘, [ParentObject])
                                - ( CHARINDEX(‘Slot‘, [ParentObject]) +4 ) )
                              -2) AS[Slot ID] ,
                    [AllocUnitId] ,
                    SUBSTRING(( SELECTREPLACE(STUFF(( SELECTREPLACE(SUBSTRING([Value],
                                                              CHARINDEX(‘:‘,
                                                              [Value]) +1,
                                                              CHARINDEX(‘†‘,
                                                              [Value])
                                                              -CHARINDEX(‘:‘,
                                                              [Value])), ‘†‘,
                                                              ‘‘)
                                                        FROM@pagedata C
                                                        WHERE B.[Page ID]= C.[Page ID]ANDSUBSTRING(B.[ParentObject],
                                                              CHARINDEX(‘Slot‘,
                                                              B.[ParentObject])
                                                              +4,
                                                              ( CHARINDEX(‘Offset‘,
                                                              B.[ParentObject])
                                                              - ( CHARINDEX(‘Slot‘,
                                                              B.[ParentObject])
                                                              +4 ) )) =SUBSTRING(C.[ParentObject],
                                                              CHARINDEX(‘Slot‘,
                                                              C.[ParentObject])
                                                              +4,
                                                              ( CHARINDEX(‘Offset‘,
                                                              C.[ParentObject])
                                                              - ( CHARINDEX(‘Slot‘,
                                                              C.[ParentObject])
                                                              +4 ) ))
                                                              AND[Object]LIKE‘%Memory Dump%‘ORDERBY‘0x‘+LEFT([Value],
                                                              CHARINDEX(‘:‘,
                                                              [Value]) -1)
                                                      FOR
                                                        XML PATH(‘‘)
                                                      ), 1, 1, ‘‘), ‘‘, ‘‘)
                              ), 1, 20000) AS[Value] ,
                    SUBSTRING(( SELECT‘0x‘+REPLACE(STUFF(( SELECTREPLACE(SUBSTRING([Value],
                                                              CHARINDEX(‘:‘,
                                                              [Value]) +1,
                                                              CHARINDEX(‘†‘,
                                                              [Value])
                                                              -CHARINDEX(‘:‘,
                                                              [Value])), ‘†‘,
                                                              ‘‘)
                                                          FROM@pagedata C
                                                          WHERE
                                                              B.[Page ID]= C.[Page ID]ANDSUBSTRING(B.[ParentObject],
                                                              CHARINDEX(‘Slot‘,
                                                              B.[ParentObject])
                                                              +4,
                                                              ( CHARINDEX(‘Offset‘,
                                                              B.[ParentObject])
                                                              - ( CHARINDEX(‘Slot‘,
                                                              B.[ParentObject])
                                                              +4 ) )) =SUBSTRING(C.[ParentObject],
                                                              CHARINDEX(‘Slot‘,
                                                              C.[ParentObject])
                                                              +4,
                                                              ( CHARINDEX(‘Offset‘,
                                                              C.[ParentObject])
                                                              - ( CHARINDEX(‘Slot‘,
                                                              C.[ParentObject])
                                                              +4 ) ))
                                                              AND[Object]LIKE‘%Memory Dump%‘ORDERBY‘0x‘+LEFT([Value],
                                                              CHARINDEX(‘:‘,
                                                              [Value]) -1)
                                                        FOR
                                                          XML PATH(‘‘)
                                                        ), 1, 1, ‘‘), ‘‘, ‘‘)
                              ), 7, 4) AS[Length]FROM@pagedata B
            WHERE[Object]LIKE‘%Memory Dump%‘GROUPBY[Page ID] ,
                    [FILE IDS] ,
                    [PAGE IDS] ,
                    [ParentObject] ,
                    [AllocUnitId]--,[Current LSN]ORDERBY[Slot ID]UPDATE@ModifiedRawDataSET[RowLog Len]=CONVERT(VARBINARY(8000), REVERSE(CAST(‘‘AS XML).value(‘xs:hexBinary(substring(sql:column("[RowLog Length]"),0))‘,
                                                              ‘varbinary(Max)‘)))
    FROM@ModifiedRawDataWHERE[LINK ID]=0UPDATE@ModifiedRawDataSET[RowLog Contents 0]=CAST(‘‘AS XML).value(‘xs:hexBinary(substring(sql:column("[RowLog Contents 0_var]"),0))‘,
                                                        ‘varbinary(Max)‘)
    FROM@ModifiedRawDataWHERE[LINK ID]=0UPDATE  B
    SET     B.[RowLog Contents 0]= ( CASEWHEN A.[RowLog Contents 0]ISNOTNULLAND C.[RowLog Contents 0]ISNOTNULLTHEN A.[RowLog Contents 0]+ C.[RowLog Contents 0]WHEN A.[RowLog Contents 0]ISNULLAND C.[RowLog Contents 0]ISNOTNULLTHEN C.[RowLog Contents 0]WHEN A.[RowLog Contents 0]ISNOTNULLAND C.[RowLog Contents 0]ISNULLTHEN A.[RowLog Contents 0]END ) ,
            B.[Update]=ISNULL(B.[Update], 0) +1FROM@ModifiedRawData B
            LEFTJOIN@ModifiedRawData A ON A.[Page IDS]=CONVERT(INT, CONVERT(VARBINARY(MAX), REVERSE(SUBSTRING(B.[RowLog Contents 0],
                                                              15+14, 2))))
                                            AND A.[File IDS]=CONVERT(INT, CONVERT(VARBINARY(MAX), REVERSE(SUBSTRING(B.[RowLog Contents 0],
                                                              19+14, 2))))
                                            AND A.[Link ID]= B.[Link ID]LEFTJOIN@ModifiedRawData C ON C.[Page IDS]=CONVERT(INT, CONVERT(VARBINARY(MAX), REVERSE(SUBSTRING(B.[RowLog Contents 0],
                                                              27+14, 2))))
                                            AND C.[File IDS]=CONVERT(INT, CONVERT(VARBINARY(MAX), REVERSE(SUBSTRING(B.[RowLog Contents 0],
                                                              31+14, 2))))
                                            AND C.[Link ID]= B.[Link ID]WHERE   ( A.[RowLog Contents 0]ISNOTNULLOR C.[RowLog Contents 0]ISNOTNULL
            )
 
 
    UPDATE  B
    SET     B.[RowLog Contents 0]= ( CASEWHEN A.[RowLog Contents 0]ISNOTNULLAND C.[RowLog Contents 0]ISNOTNULLTHEN A.[RowLog Contents 0]+ C.[RowLog Contents 0]WHEN A.[RowLog Contents 0]ISNULLAND C.[RowLog Contents 0]ISNOTNULLTHEN C.[RowLog Contents 0]WHEN A.[RowLog Contents 0]ISNOTNULLAND C.[RowLog Contents 0]ISNULLTHEN A.[RowLog Contents 0]END )
    --,B.[Update]=ISNULL(B.[Update],0)+1FROM@ModifiedRawData B
            LEFTJOIN@ModifiedRawData A ON A.[Page IDS]=CONVERT(INT, CONVERT(VARBINARY(MAX), REVERSE(SUBSTRING(B.[RowLog Contents 0],
                                                              15+14, 2))))
                                            AND A.[File IDS]=CONVERT(INT, CONVERT(VARBINARY(MAX), REVERSE(SUBSTRING(B.[RowLog Contents 0],
                                                              19+14, 2))))
                                            AND A.[Link ID]<> B.[Link ID]AND B.[Update]=0LEFTJOIN@ModifiedRawData C ON C.[Page IDS]=CONVERT(INT, CONVERT(VARBINARY(MAX), REVERSE(SUBSTRING(B.[RowLog Contents 0],
                                                              27+14, 2))))
                                            AND C.[File IDS]=CONVERT(INT, CONVERT(VARBINARY(MAX), REVERSE(SUBSTRING(B.[RowLog Contents 0],
                                                              31+14, 2))))
                                            AND C.[Link ID]<> B.[Link ID]AND B.[Update]=0WHERE   ( A.[RowLog Contents 0]ISNOTNULLOR C.[RowLog Contents 0]ISNOTNULL
            )
 
    UPDATE@ModifiedRawDataSET[RowLog Contents 0]= ( CASEWHEN[RowLog Len]>=8000THENSUBSTRING([RowLog Contents 0],
                                                        15, [RowLog Len])
                                         WHEN[RowLog Len]<8000THENSUBSTRING([RowLog Contents 0],
                                                        15+6,
                                                        CONVERT(INT, CONVERT(VARBINARY(MAX), REVERSE(SUBSTRING([RowLog Contents 0],
                                                              15, 6)))))
                                    END )
    FROM@ModifiedRawDataWHERE[LINK ID]=0UPDATE@ColumnNameAndDataSET[hex_Value]=[RowLog Contents 0]--,A.[Update]=A.[Update]+1FROM@ColumnNameAndData A
            INNERJOIN@ModifiedRawData B ONCONVERT(INT, CONVERT(VARBINARY(MAX), REVERSE(SUBSTRING([hex_value],
                                                              17, 4)))) =[PAGE IDS]ANDCONVERT(INT, SUBSTRING([hex_value],
                                                              9, 2)) = B.[Link ID]WHERE[System_Type_Id]IN ( 99, 167, 175, 231, 239, 241, 165, 98 )
            AND[Link ID]<>0UPDATE@ColumnNameAndDataSET[hex_Value]= ( CASEWHEN B.[RowLog Contents 0]ISNOTNULLAND C.[RowLog Contents 0]ISNOTNULLTHEN B.[RowLog Contents 0]+ C.[RowLog Contents 0]WHEN B.[RowLog Contents 0]ISNULLAND C.[RowLog Contents 0]ISNOTNULLTHEN C.[RowLog Contents 0]WHEN B.[RowLog Contents 0]ISNOTNULLAND C.[RowLog Contents 0]ISNULLTHEN B.[RowLog Contents 0]END )
    --,A.[Update]=A.[Update]+1FROM@ColumnNameAndData A
            LEFTJOIN@ModifiedRawData B ONCONVERT(INT, CONVERT(VARBINARY(MAX), REVERSE(SUBSTRING([hex_value],
                                                              5, 4)))) = B.[PAGE IDS]AND B.[Link ID]=0LEFTJOIN@ModifiedRawData C ONCONVERT(INT, CONVERT(VARBINARY(MAX), REVERSE(SUBSTRING([hex_value],
                                                              17, 4)))) = C.[PAGE IDS]AND C.[Link ID]=0WHERE[System_Type_Id]IN ( 99, 167, 175, 231, 239, 241, 165, 98 )
            AND ( B.[RowLog Contents 0]ISNOTNULLOR C.[RowLog Contents 0]ISNOTNULL
                )
 
    UPDATE@ColumnNameAndDataSET[hex_Value]=[RowLog Contents 0]--,A.[Update]=A.[Update]+1FROM@ColumnNameAndData A
            INNERJOIN@ModifiedRawData B ONCONVERT(INT, CONVERT(VARBINARY(MAX), REVERSE(SUBSTRING([hex_value],
                                                              9, 4)))) =[PAGE IDS]ANDCONVERT(INT, SUBSTRING([hex_value],
                                                              3, 2)) =[Link ID]WHERE[System_Type_Id]IN ( 35, 34, 99 )
            AND[Link ID]<>0UPDATE@ColumnNameAndDataSET[hex_Value]=[RowLog Contents 0]--,A.[Update]=A.[Update]+10FROM@ColumnNameAndData A
            INNERJOIN@ModifiedRawData B ONCONVERT(INT, CONVERT(VARBINARY(MAX), REVERSE(SUBSTRING([hex_value],
                                                              9, 4)))) =[PAGE IDS]WHERE[System_Type_Id]IN ( 35, 34, 99 )
            AND[Link ID]=0UPDATE@ColumnNameAndDataSET[hex_Value]=[RowLog Contents 0]--,A.[Update]=A.[Update]+1FROM@ColumnNameAndData A
            INNERJOIN@ModifiedRawData B ONCONVERT(INT, CONVERT(VARBINARY(MAX), REVERSE(SUBSTRING([hex_value],
                                                              15, 4)))) =[PAGE IDS]WHERE[System_Type_Id]IN ( 35, 34, 99 )
            AND[Link ID]=0UPDATE@ColumnNameAndDataSET[hex_value]=0xFFFE+SUBSTRING([hex_value], 9, LEN([hex_value]))
    --,[Update]=[Update]+1WHERE[system_type_id]=241CREATETABLE[#temp_Data]
        (
          [FieldName]VARCHAR(MAX) ,
          [FieldValue]NVARCHAR(MAX) ,
          [Rowlogcontents]VARBINARY(8000) ,
          [Row ID]INT
        )
 
    INSERTINTO #temp_Data
            SELECT  NAME ,
                    CASEWHEN system_type_id IN ( 231, 239 )
                         THENLTRIM(RTRIM(CONVERT(NVARCHAR(MAX), hex_Value)))  --NVARCHAR ,NCHARWHEN system_type_id IN ( 167, 175 )
                         THENLTRIM(RTRIM(CONVERT(VARCHAR(MAX), hex_Value)))  --VARCHAR,CHARWHEN system_type_id IN ( 35 )
                         THENLTRIM(RTRIM(CONVERT(VARCHAR(MAX), hex_Value))) --TextWHEN system_type_id IN ( 99 )
                         THENLTRIM(RTRIM(CONVERT(NVARCHAR(MAX), hex_Value))) --nText WHEN system_type_id =48THENCONVERT(VARCHAR(MAX), CONVERT(TINYINT, CONVERT(BINARY(1), REVERSE(hex_Value)))) --TINY INTEGERWHEN system_type_id =52THENCONVERT(VARCHAR(MAX), CONVERT(SMALLINT, CONVERT(BINARY(2), REVERSE(hex_Value)))) --SMALL INTEGERWHEN system_type_id =56THENCONVERT(VARCHAR(MAX), CONVERT(INT, CONVERT(BINARY(4), REVERSE(hex_Value)))) -- INTEGERWHEN system_type_id =127THENCONVERT(VARCHAR(MAX), CONVERT(BIGINT, CONVERT(BINARY(8), REVERSE(hex_Value))))-- BIG INTEGERWHEN system_type_id =61THENCONVERT(VARCHAR(MAX), CONVERT(DATETIME, CONVERT(VARBINARY(8000), REVERSE(hex_Value))), 100) --DATETIMEWHEN system_type_id =58THENCONVERT(VARCHAR(MAX), CONVERT(SMALLDATETIME, CONVERT(VARBINARY(8000), REVERSE(hex_Value))), 100) --SMALL DATETIMEWHEN system_type_id =108THENCONVERT(VARCHAR(MAX), CONVERT(NUMERIC(38, 20), CONVERT(VARBINARY, CONVERT(VARBINARY(1), xprec)
                              +CONVERT(VARBINARY(1), xscale))
                              +CONVERT(VARBINARY(1), 0) + hex_Value)) --- NUMERICWHEN system_type_id =106THENCONVERT(VARCHAR(MAX), CONVERT(DECIMAL(38, 20), CONVERT(VARBINARY, CONVERT(VARBINARY(1), xprec)
                              +CONVERT(VARBINARY(1), xscale))
                              +CONVERT(VARBINARY(1), 0) + hex_Value)) --- DECIMALWHEN system_type_id IN ( 60, 122 )
                         THENCONVERT(VARCHAR(MAX), CONVERT(MONEY, CONVERT(VARBINARY(8000), REVERSE(hex_Value))), 2) --MONEY,SMALLMONEYWHEN system_type_id =104THENCONVERT(VARCHAR(MAX), CONVERT (BIT, CONVERT(BINARY(1), hex_Value)
                              %2))  -- BITWHEN system_type_id =62THENRTRIM(LTRIM(STR(CONVERT(FLOAT, SIGN(CAST(CONVERT(VARBINARY(8000), REVERSE(hex_Value)) ASBIGINT))
                                              * ( 1.0+ ( CAST(CONVERT(VARBINARY(8000), REVERSE(hex_Value)) ASBIGINT)
                                                      &0x000FFFFFFFFFFFFF )
                                                  *POWER(CAST(2ASFLOAT),
                                                          -52) )
                                              *POWER(CAST(2ASFLOAT),
                                                      ( ( CAST(CONVERT(VARBINARY(8000), REVERSE(hex_Value)) ASBIGINT)
                                                          &0x7ff0000000000000 )
                                                        /EXP(52*LOG(2))
                                                        -1023 ))), 53,
                                              LEN(hex_Value)))) --- FLOATWHEN system_type_id =59THENLEFT(LTRIM(STR(CAST(SIGN(CAST(CONVERT(VARBINARY(8000), REVERSE(hex_Value)) ASBIGINT))
                                             * ( 1.0+ ( CAST(CONVERT(VARBINARY(8000), REVERSE(hex_Value)) ASBIGINT)
                                                     &0x007FFFFF )
                                                 *POWER(CAST(2ASREAL), -23) )
                                             *POWER(CAST(2ASREAL),
                                                     ( ( ( CAST(CONVERT(VARBINARY(8000), REVERSE(hex_Value)) ASINT) )
                                                         &0x7f800000 )
                                                       /EXP(23*LOG(2))
                                                       -127 )) ASREAL), 23,
                                             23)), 8) --RealWHEN system_type_id IN ( 165, 173 )
                         THEN ( CASEWHENCHARINDEX(0x,
                                                    CAST(‘‘AS XML).value(‘xs:hexBinary(sql:column("hex_Value"))‘,
                                                              ‘VARBINARY(8000)‘)) =0THEN‘0x‘ELSE‘‘END ) +CAST(‘‘AS XML).value(‘xs:hexBinary(sql:column("hex_Value"))‘,
                                                              ‘varchar(max)‘) -- BINARY,VARBINARYWHEN system_type_id =34THEN ( CASEWHENCHARINDEX(0x,
                                                    CAST(‘‘AS XML).value(‘xs:hexBinary(sql:column("hex_Value"))‘,
                                                              ‘VARBINARY(8000)‘)) =0THEN‘0x‘ELSE‘‘END ) +CAST(‘‘AS XML).value(‘xs:hexBinary(sql:column("hex_Value"))‘,
                                                              ‘varchar(max)‘)  --IMAGEWHEN system_type_id =36THENCONVERT(VARCHAR(MAX), CONVERT(UNIQUEIDENTIFIER, hex_Value)) --UNIQUEIDENTIFIERWHEN system_type_id =231THENCONVERT(VARCHAR(MAX), CONVERT(SYSNAME, hex_Value)) --SYSNAMEWHEN system_type_id =241THENCONVERT(VARCHAR(MAX), CONVERT(XML, hex_Value)) --XMLWHEN system_type_id =189THEN ( CASEWHENCHARINDEX(0x,
                                                    CAST(‘‘AS XML).value(‘xs:hexBinary(sql:column("hex_Value"))‘,
                                                              ‘VARBINARY(8000)‘)) =0THEN‘0x‘ELSE‘‘END ) +CAST(‘‘AS XML).value(‘xs:hexBinary(sql:column("hex_Value"))‘,
                                                              ‘varchar(max)‘) --TIMESTAMPWHEN system_type_id =98THEN ( CASEWHENCONVERT(INT, SUBSTRING(hex_Value, 1,
                                                              1)) =56THENCONVERT(VARCHAR(MAX), CONVERT(INT, CONVERT(BINARY(4), REVERSE(SUBSTRING(hex_Value,
                                                              3,
                                                              LEN(hex_Value))))))  -- INTEGERWHENCONVERT(INT, SUBSTRING(hex_Value, 1,
                                                              1)) =108THENCONVERT(VARCHAR(MAX), CONVERT(NUMERIC(38,
                                                              20), CONVERT(VARBINARY(1), SUBSTRING(hex_Value,
                                                              3, 1))
                                          +CONVERT(VARBINARY(1), SUBSTRING(hex_Value,
                                                              4, 1))
                                          +CONVERT(VARBINARY(1), 0)
                                          +SUBSTRING(hex_Value, 5,
                                                      LEN(hex_Value)))) --- NUMERICWHENCONVERT(INT, SUBSTRING(hex_Value, 1,
                                                              1)) =167THENLTRIM(RTRIM(CONVERT(VARCHAR(MAX), SUBSTRING(hex_Value,
                                                              9,
                                                              LEN(hex_Value))))) --VARCHAR,CHARWHENCONVERT(INT, SUBSTRING(hex_Value, 1,
                                                              1)) =36THENCONVERT(VARCHAR(MAX), CONVERT(UNIQUEIDENTIFIER, SUBSTRING(( hex_Value ),
                                                              3, 20))) --UNIQUEIDENTIFIERWHENCONVERT(INT, SUBSTRING(hex_Value, 1,
                                                              1)) =61THENCONVERT(VARCHAR(MAX), CONVERT(DATETIME, CONVERT(VARBINARY(8000), REVERSE(SUBSTRING(hex_Value,
                                                              3,
                                                              LEN(hex_Value))))), 100) --DATETIMEWHENCONVERT(INT, SUBSTRING(hex_Value, 1,
                                                              1)) =165THEN‘0x‘+SUBSTRING(( CASEWHENCHARINDEX(0x,
                                                              CAST(‘‘AS XML).value(‘xs:hexBinary(sql:column("hex_Value"))‘,
                                                              ‘VARBINARY(8000)‘)) =0THEN‘0x‘ELSE‘‘END )
                                                      +CAST(‘‘AS XML).value(‘xs:hexBinary(sql:column("hex_Value"))‘,
                                                              ‘varchar(max)‘),
                                                      11, LEN(hex_Value)) -- BINARY,VARBINARYEND )
                    ENDAS FieldValue ,
                    [Rowlogcontents] ,
                    [Row ID]FROM@ColumnNameAndDataORDERBY nullbit
 
--Create the column name in the same order to do pivot table.DECLARE@FieldNameVARCHAR(MAX)
    SET@FieldName=STUFF(( SELECT‘,‘+CAST(QUOTENAME([Name]) ASVARCHAR(MAX))
                             FROM   syscolumns
                             WHERE  id =OBJECT_ID(‘‘+@SchemaName_n_TableName+‘‘)
                           FOR
                             XML PATH(‘‘)
                           ), 1, 1, ‘‘)
 
--Finally did pivot table and get the data back in the same format.SET@sql=‘SELECT ‘+@FieldName+‘ FROM #temp_Data PIVOT (Min([FieldValue]) FOR FieldName IN (‘+@FieldName+‘)) AS pvt‘EXEC sp_executesql @sqlGO

 

恢复你的数据

--恢复数据,不加时间段条件  参数:数据库名,表名
--EXAMPLE #1 : FOR ALL DELETED RECORDSEXEC Recover_Deleted_Data_Proc ‘test‘,‘dbo.aa‘GO--恢复数据,加时间段条件
--EXAMPLE #2 : FOR ANY SPECIFIC DATE RANGEEXEC Recover_Deleted_Data_Proc ‘test‘,‘dbo.aa‘,‘2014-04-23‘,‘2014-04-23‘

 

执行了下面的存储过程之后你会发现会显示出刚才删除的数据

EXEC Recover_Deleted_Data_Proc ‘test‘,‘dbo.aa‘GO

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解释

究竟他是如何工作的?让我们来一步一步来,这个过程涉及到7个步骤:

步骤1:

我们需要获得SQLSERVER删除的数据记录.使用标准SQLSERVER函数fn_dblog,我们能够容易的获得事务日志记录(包括

已删的数据。不过,我们只需要事务日志中选中的被删数据,所以我们的过滤条件需要包含3个字段 Context, Operation & AllocUnitName)

 

We need to get the deleted records from sql server. By using the standard SQL Server function fn_blog, we can easily get all transaction log (Including deleted data. But, we need only the selected deleted records from the transaction log. So we included three filters (Context, Operation , AllocUnitName).

  • Context (‘LCX_MARK_AS_GHOST’and ‘LCX_HEAP’)
  • Operation (‘LOP_DELETE_ROWS’)
  • AllocUnitName(‘dbo.aa’) –- Schema + table Name

 

Context可以说明是堆表还是聚集表

Operation:删除操作

AllocUnitName:分配单元名称,表名

下面是一个代码片段

SELECT[RowLog Contents 0]FROM    sys.fn_dblog(NULL, NULL)
WHERE   AllocUnitName =‘dbo.aa‘AND Context IN ( ‘LCX_MARK_AS_GHOST‘, ‘LCX_HEAP‘ )
        AND Operation IN ( ‘LOP_DELETE_ROWS‘ )

这个查询会返回不同列的信息,但是我们只需要选择[RowLog Contents 0]列,去获得被删除的数据的内容

RowLog content 0列的内容类似于这样

“0x300018000100000000000000006B0000564920205900000

00500E001002800426F62206A65727279″

 

 

步骤2:

现在,我们已经删除了数据,这些数据以hex码的形式放在事务日志里,这些hex码是有规律的,我们根据这些规律可以很容易恢复这些数据。

不过在恢复这些数据之前,我们需要理解这些格式。这些格式在KalenDelaney’s SQL Internal’s book.的书里面有讲解

 

  • 1 Byte : Status Bit A
  • 1 Byte : Status Bit B
  • 2 Bytes : Fixed length size
  • n Bytes : Fixed length data
  • 2 Bytes : Total Number of Columns
  • n Bytes : NULL Bitmap (1 bit for each column as 1 indicates that the column is null and 0 indicate that the column is not null)
  • 2 Bytes : Number of variable-length columns
  • n Bytes : Column offset array (2x variable length column)
  • n Bytes : Data for variable length columns

所以, hex码的“RowLog content 0″列的内容就等价于

“Status Bit A +Status Bit B +Fixed length size +Fixed length data +Total Number of Columns +NULL Bitmap +Number of variable-length columns +NULL Bitmap+Number of variable-length columns +Column offset array +Data for variable length columns.”

 

更详细的可以参考:SQL Server2008存储结构之堆表、行溢出

关于数据行的结构我们还可以采用稍微宏观一些的视角来查看。

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步骤3:

现在,我们需要解剖RowLog Content o列的内容(我们删除的数据的Hex码),利用上面的数据行的结构

  • [Fixed Length Data] = Substring (RowLog content 0, Status Bit A+Status Bit B + 1,2 bytes)
  • [Total No of Columns]= Substring (RowLog content 0, [Fixed Length Data] + 1,2 bytes)
  • [Null Bitmap length] = Ceiling ([Total No of Columns]/8.0)
  • [Null Bytes]= Substring (RowLog content 0, Status Bit A+ Status Bit B +[Fixed Length Data] +1, [Null Bitmap length] )
  • Total no of variable columns = Substring (RowLog content 0, Status Bit A+ Status Bit B + [Fixed Length Data] +1, [Null Bitmap length] + 2 )
  • Column Offset Array= Substring (RowLog content 0, Status Bit A+ Status Bit B + [Fixed Length Data] +1, [Null Bitmap length] + 2 , Total no of variable columns*2 )
  • Variable Column Start = Status Bit A+ Status Bit B + [Fixed Length Data] + [Null Bitmap length] + 2+( Total no of variable columns*2)

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步骤4:

现在我们已经将hex码切开了(0x300008000100000002000001001300604F7D59),所以,我们能找到删除的行的某列的数据是否为null值

根据NULL位图。为了完成将NULL Bytes的hex码转换为二进制格式(正如之前讨论的,1表示行中对应的那一列为null,而0则表示对应的列有实际的数据)

如果还不是明白的童鞋可以看一下我写的这篇文章:《SQLSERVER中NULL位图的作用

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步骤5:

现在,我们已经做了初步的数据分割 (Step-3) 和null值判断(Step-4) 。然后我们需要使用代码片段去获得列数据,例如:列名,列大小,精度,范围

和最重要的叶子的null位(确保列数据是固定长度的(<=-1表示可变长度)或者固定长度的(>=1))

使用下面的SQL语句

SELECT*FROM    sys.allocation_units allocunits
        INNERJOIN sys.partitions partitions ON ( allocunits.type IN ( 1, 3 )
                                                  AND partitions.hobt_id = allocunits.container_id
                                                )
                                                OR ( allocunits.type =2AND partitions.partition_id = allocunits.container_id
                                                   )
        INNERJOIN sys.system_internals_partition_columns cols ON cols.partition_id = partitions.partition_id
        LEFTOUTERJOIN syscolumns ON syscolumns.id = partitions.object_idAND syscolumns.colid = cols.partition_column_id

与(Step-1,2,3,4) 获得的数据表做join连接,根据allocunits.[Allocation_Unit_Id]。

现在我们知道表和表中的数据信息,那么我们需要利用这些数据去将 [RowLog Contents 0] 列里的hex码的数据插入到表中的相应列

现在我们需要关心每一列的数据究竟是固定长度的还是可变长度的

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步骤6:

我们收集了每列的hex格式的数据。现在我们需要利用[System_type_id]去转换这些数据回去正确的数据类型

每一种数据类型都有不同的数据类型转换机制。

--NVARCHAR ,NCHARWHEN system_type_id IN (231, 239) THENLTRIM(RTRIM(CONVERT(NVARCHAR(max),hex_Value)))
 
--VARCHAR,CHARWHEN system_type_id IN (167,175) THENLTRIM(RTRIM(CONVERT(VARCHAR(max),REPLACE(hex_Value, 0x00, 0x20))))
 
--TINY INTEGERWHEN system_type_id =48THENCONVERT(VARCHAR(MAX), CONVERT(TINYINT, CONVERT(BINARY(1), REVERSE (hex_Value))))
 
--SMALL INTEGERWHEN system_type_id =52THENCONVERT(VARCHAR(MAX), CONVERT(SMALLINT, CONVERT(BINARY(2), REVERSE (hex_Value))))
 
-- INTEGERWHEN system_type_id =56THENCONVERT(VARCHAR(MAX), CONVERT(INT, CONVERT(BINARY(4), REVERSE(hex_Value))))
 
-- BIG INTEGERWHEN system_type_id =127THENCONVERT(VARCHAR(MAX), CONVERT(BIGINT, CONVERT(BINARY(8), REVERSE(hex_Value))))
 
--DATETIMEWHEN system_type_id =61ThenCONVERT(VARCHAR(Max),CONVERT(DATETIME,Convert(VARBINARY(max),REVERSE (hex_Value))),100)
 
--SMALL DATETIMEWHEN system_type_id =58ThenCONVERT(VARCHAR(Max),CONVERT(SMALLDATETIME,CONVERT(VARBINARY(MAX),REVERSE(hex_Value))),100) --SMALL DATETIME--- NUMERICWHEN system_type_id =108THENCONVERT(VARCHAR(MAX), CAST(CONVERT(NUMERIC(18,14), CONVERT(VARBINARY,CONVERT(VARBINARY,xprec)+CONVERT(VARBINARY,xscale))+CONVERT(VARBINARY(1),0) + hex_Value) asFLOAT))
 
--MONEY,SMALLMONEYWHEN system_type_id In(60,122) THENCONVERT(VARCHAR(MAX),Convert(MONEY,Convert(VARBINARY(MAX),Reverse(hex_Value))),2)
 
--- DECIMALWHEN system_type_id =106THENCONVERT(VARCHAR(MAX), CAST(CONVERT(Decimal(38,34), Convert(VARBINARY,Convert(VARBINARY,xprec)+CONVERT(VARBINARY,xscale))+CONVERT(VARBINARY(1),0) + hex_Value) asFLOAT))
 
-- BITWHEN system_type_id =104THENCONVERT(VARCHAR(MAX),CONVERT (BIT,CONVERT(BINARY(1), hex_Value)%2))
 
--- FLOATWHEN system_type_id =62THENRTRIM(LTRIM(Str(Convert(FLOAT,SIGN(CAST(Convert(VARBINARY(max),Reverse(hex_Value)) ASBIGINT)) * (1.0+ (CAST(CONVERT(VARBINARY(max),Reverse(hex_Value)) ASBIGINT) &0x000FFFFFFFFFFFFF) *POWER(CAST(2ASFLOAT), -52)) *POWER(CAST(2ASFLOAT),((CAST(CONVERT(VARBINARY(max),Reverse(hex_Value)) ASBIGINT) &0x7ff0000000000000) /EXP(52*LOG(2))-1023))),53,LEN(hex_Value))))
 
--REALWhen  system_type_id =59THENLeft(LTRIM(STR(Cast(SIGN(CAST(Convert(VARBINARY(max),Reverse(hex_Value)) ASBIGINT))* (1.0+ (CAST(CONVERT(VARBINARY(max),Reverse(hex_Value)) ASBIGINT) &0x007FFFFF) *POWER(CAST(2ASReal), -23)) *POWER(CAST(2ASReal),(((CAST(CONVERT(VARBINARY(max),Reverse(hex_Value)) ASINT) )&0x7f800000)/EXP(23*LOG(2))-127))ASREAL),23,23)),8)
 
--BINARY,VARBINARYWHEN system_type_id In (165,173) THEN (CASEWHENCharindex(0x,cast(‘‘AS XML).value(‘xs:hexBinary(sql:column("hex_value"))‘, ‘varbinary(max)‘)) =0THEN‘0x‘ELSE‘‘END) +cast(‘‘AS XML).value(‘xs:hexBinary(sql:column("hex_value"))‘, ‘varchar(max)‘) 
 
--UNIQUEIDENTIFIER WHEN system_type_id =36THENCONVERT(VARCHAR(MAX),CONVERT(UNIQUEIDENTIFIER,hex_Value)) 

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步骤7:

最终我们做一个数据透视表,你会看到最后的结果:被删的数据回来了!

注意:这些数据只是展示出来并没有自动插入回表中,你需要将这些数据重新插入回去表中!

技术分享


我的测试

经过测试,作者写的这个存储过程还是有些问题

如果你创建的测试表的数据类型有xml或者是一些text数据类型的字段会有报错

 

Msg 537, Level16, State 3, Procedure Recover_Deleted_Data_Proc, Line 525
Invalid length parameter passed to the LEFTorSUBSTRINGfunction.

Msg 9420, Level16, State 1, Procedure Recover_Deleted_Data_Proc, Line 651
XML parsing: line 1, character2, illegal xml character

但是一般的数据类型则不会,例如nvarchar这些

 

还有不要在存储过程的最后加

--Recover the deleted data without date rangeEXEC Recover_Deleted_Data_Proc ‘test‘,‘dbo.Test_Table‘GO--Recover the deleted data it with date rangeEXEC Recover_Deleted_Data_Proc ‘test‘,‘dbo.Test_Table‘,‘2012-06-01‘,‘2012-06-30‘

否则会报错

消息 50000,级别 16,状态 1,过程 Recover_Deleted_Data_Proc,第 290 行
There is no data in the logas per the search criteria

总结

 

实际上这个存储过程还是挺有研究意义的,对于想做一个跟Log Explorer for SQL Server软件功能差不多的软件出来

还是有可能的,跟着作者的思路,一步一步实现

苦于最近太忙,先分享出来,以后再研究这个存储过程了~

转 --- 恢复误删数据

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原文地址:http://www.cnblogs.com/Frank99/p/5951222.html

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