Msg 537, Level 16, State 3, Procedure Recover_Truncated_Data_Proc, Line 113 Invalid length parameter passed to the LEFT or SUBSTRING function.

ahmed salah 3,216 Reputation points
2021-04-08T21:04:32.883+00:00

I work on sql server 2012 i call procedure name as below
EXEC Recover_Truncated_Data_Proc 'Nahdy','dbo.Student'
I get error
Msg 537, Level 16, State 3, Procedure Recover_Truncated_Data_Proc, Line 113 Invalid length parameter passed to the LEFT or SUBSTRING function.
so How to solve this issue please

this table dbo.Student

USE [Nahdy]
GO

/****** Object:  Table [dbo].[Student]    Script Date: 4/8/2021 11:02:03 PM ******/
SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO

SET ANSI_PADDING ON
GO

CREATE TABLE [dbo].[Student](
    [Sno] [int] NOT NULL,
    [Student ID] [nvarchar](6) NOT NULL,
    [Student name] [varchar](50) NOT NULL,
    [Date of Birth] [datetime] NOT NULL,
    [Weight] [int] NULL
) ON [Data Filegroup 1]

GO

SET ANSI_PADDING OFF
GO

procedure as below

alter PROCEDURE Recover_Truncated_Data_Proc
@Database_Name NVARCHAR(MAX),
@SchemaName_n_TableName NVARCHAR(MAX),
@Date_From datetime='1900/01/01',
@Date_To datetime ='9999/12/31'
AS
DECLARE @Fileid INT
DECLARE @Pageid INT
DECLARE @Slotid INT

DECLARE @ConsolidatedPageID VARCHAR(MAX)
Declare @AllocUnitID as bigint
Declare @TransactionID as VARCHAR(MAX)

/*  Pick The actual data
*/
declare @temppagedata table
(
[ParentObject] sysname,
[Object] sysname,
[Field] sysname,
[Value] sysname)

declare @pagedata table
(
[Page ID] sysname,
[AllocUnitId] bigint,
[ParentObject] sysname,
[Object] sysname,
[Field] sysname,
[Value] sysname)


    DECLARE Page_Data_Cursor CURSOR FOR
    /*We need to filter LOP_MODIFY_ROW,LOP_MODIFY_COLUMNS from log for modified records & Get its Slot No, Page ID & AllocUnit ID*/
    SELECT LTRIM(RTRIM(Replace([Description],'Deallocated',''))) AS [PAGE ID]
    ,[Slot ID],[AllocUnitId]
    FROM    sys.fn_dblog(NULL, NULL)  
    WHERE   
    AllocUnitId IN
    (Select [Allocation_unit_id] from sys.allocation_units allocunits
    INNER JOIN sys.partitions partitions ON (allocunits.type IN (1, 3)  
    AND partitions.hobt_id = allocunits.container_id) OR (allocunits.type = 2 
    AND partitions.partition_id = allocunits.container_id)  
    Where object_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 (SELECT DISTINCT [TRANSACTION ID] FROM    sys.fn_dblog(NULL, NULL) 
    WHERE Context IN ('LCX_NULL') AND Operation in ('LOP_BEGIN_XACT')  
    AND [Transaction Name]='TRUNCATE TABLE'
    AND  CONVERT(NVARCHAR(11),[Begin Time]) BETWEEN @Date_From AND @Date_To)

    /****************************************/

    GROUP BY [Description],[Slot ID],[AllocUnitId]
    ORDER BY [Slot ID]    

    OPEN Page_Data_Cursor

    FETCH NEXT FROM Page_Data_Cursor INTO @ConsolidatedPageID, @Slotid,@AllocUnitID

    WHILE @@FETCH_STATUS = 0
    BEGIN
        DECLARE @hex_pageid AS VARCHAR(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 ID
        SET @hex_pageid ='0x'+ SUBSTRING(@ConsolidatedPageID,CHARINDEX(':',@ConsolidatedPageID)+1,Len(@ConsolidatedPageID))  ---Seperate the page ID
        SELECT @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 integer
        FROM (SELECT CASE substring(@hex_pageid, 1, 2) WHEN '0x' THEN 3 ELSE 0 END) AS t(pos) 

        DELETE @temppagedata
        -- Now we need to get the actual data (After truncate) from the page

        INSERT INTO @temppagedata EXEC( 'DBCC PAGE(' + @DataBase_Name + ', ' + @fileid + ', ' + @pageid + ', 1) with tableresults,no_infomsgs;'); 
        ---Check if any index page is there
        If (Select Count(*) From @temppagedata Where [Field]='Record Type' And [Value]='INDEX_RECORD')=0
        Begin
            DELETE @temppagedata
            INSERT INTO @temppagedata EXEC( 'DBCC PAGE(' + @DataBase_Name + ', ' + @fileid + ', ' + @pageid + ', 3) with tableresults,no_infomsgs;'); 
        End
        Else
        Begin
           DELETE @temppagedata
        End

        INSERT INTO @pagedata SELECT @ConsolidatedPageID,@AllocUnitID,[ParentObject],[Object],[Field] ,[Value] FROM @temppagedata
        FETCH NEXT FROM Page_Data_Cursor INTO  @ConsolidatedPageID, @Slotid,@AllocUnitID
    END

CLOSE Page_Data_Cursor
DEALLOCATE Page_Data_Cursor

DECLARE @Newhexstring VARCHAR(MAX);

DECLARE @ModifiedRawData TABLE
(
  [ID] INT IDENTITY(1,1),
  [PAGE ID] VARCHAR(MAX),
  [Slot ID] INT,
  [AllocUnitId] BIGINT,
  [RowLog Contents 0_var] VARCHAR(MAX),
  [RowLog Contents 0] VARBINARY(8000)
)
--print N'before issue';
--The truncated 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 format

INSERT INTO @ModifiedRawData ([PAGE ID],[Slot ID],[AllocUnitId]
,[RowLog Contents 0_var])
SELECT [Page ID],Substring([ParentObject],CHARINDEX('Slot', [ParentObject])+4, (CHARINDEX('Offset', [ParentObject])-(CHARINDEX('Slot', [ParentObject])+4)) ) as [Slot ID]
,[AllocUnitId]
,(
SELECT REPLACE(STUFF((SELECT REPLACE(SUBSTRING([Value],CHARINDEX(':',[Value])+1,CHARINDEX('†',[Value])-CHARINDEX(':',[Value])),'†','')
FROM @pagedata C  WHERE B.[Page ID]= C.[Page ID] And Substring(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%'
FOR XML PATH('') ),1,1,'') ,' ','')
) AS [Value]
From @pagedata B
Where [Object] Like '%Memory Dump%'
Group By [Page ID],[ParentObject],[AllocUnitId]
Order By [Slot ID]

-- Convert the hex value data in string, convert it into Hex value as well. 
UPDATE @ModifiedRawData  SET [RowLog Contents 0] = cast('' AS XML).value('xs:hexBinary(substring(sql:column("[RowLog Contents 0_var]"), 0) )', 'varbinary(max)')
FROM @ModifiedRawData

DECLARE @RowLogContents VARBINARY(8000)
Declare @AllocUnitName NVARCHAR(Max)
Declare @SQL NVARCHAR(Max)
DECLARE @bitTable TABLE
(
  [ID] INT,
  [Bitvalue] INT
)
----Create table to set the bit position of one byte.

INSERT INTO @bitTable
SELECT 0,2 UNION ALL
SELECT 1,2 UNION ALL
SELECT 2,4 UNION ALL
SELECT 3,8 UNION ALL
SELECT 4,16 UNION ALL
SELECT 5,32 UNION ALL
SELECT 6,64 UNION ALL
SELECT 7,128

--Create table to collect the row data.
DECLARE @DeletedRecords TABLE
(
    [RowLogContents]    VARBINARY(8000),
    [AllocUnitID]       BIGINT,
    [Transaction ID]    NVARCHAR(Max),
    [Slot ID]           INT,
    [FixedLengthData]   SMALLINT,
    [TotalNoOfCols]     SMALLINT,
    [NullBitMapLength]  SMALLINT,
    [NullBytes]         VARBINARY(8000),
    [TotalNoofVarCols]  SMALLINT,
    [ColumnOffsetArray] VARBINARY(8000),
    [VarColumnStart]    SMALLINT,
    [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] 

,[ID] AS [Transaction ID]  

,[Slot ID] as [Slot 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 )
,(CASE WHEN SUBSTRING([RowLog Contents 0], 1, 1) In (0x30,0x70) THEN
CONVERT(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))))  ELSE null  END) AS [TotalNoofVarCols] 

--[ColumnOffsetArray]= Substring (RowLog content 0, Status Bit A+ Status Bit B + [Fixed Length Data] +1, [Null Bitmap length] + 2 , [TotalNoofVarCols]*2 )
,(CASE WHEN SUBSTRING([RowLog Contents 0], 1, 1) In (0x30,0x70) THEN
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
, (CASE WHEN SUBSTRING([RowLog Contents 0], 1, 1) In (0x30,0x70) THEN
CONVERT(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))))  ELSE null  END)
* 2)  ELSE null  END) AS [ColumnOffsetArray] 

--  Variable column Start = Status Bit A+ Status Bit B + [Fixed Length Data] + [Null Bitmap length] + 2+([TotalNoofVarCols]*2)
,CASE WHEN SUBSTRING([RowLog Contents 0], 1, 1)In (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)) 

+ ((CASE WHEN SUBSTRING([RowLog Contents 0], 1, 1) In (0x30,0x70) THEN
CONVERT(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))))  ELSE null  END) * 2)) 

ELSE null End AS [VarColumnStart]
From @ModifiedRawData
),

---Use this technique to repeate the row till the no of bytes of the row.
N1 (n) AS (SELECT 1 UNION ALL SELECT 1),
N2 (n) AS (SELECT 1 FROM N1 AS X, N1 AS Y),
N3 (n) AS (SELECT 1 FROM N2 AS X, N2 AS Y),
N4 (n) AS (SELECT ROW_NUMBER() OVER(ORDER BY X.n)
           FROM N3 AS X, N3 AS Y)

insert into @DeletedRecords
Select   RowLogContents
        ,[AllocUnitID]
        ,[Transaction ID]
        ,[Slot ID]
        ,[FixedLengthData]
        ,[TotalNoOfCols]
        ,[NullBitMapLength]
        ,[NullBytes]
        ,[TotalNoofVarCols]
        ,[ColumnOffsetArray]
        ,[VarColumnStart]
         --Get the Null value against each column (1 means null zero means not null)
        ,[NullBitMap]=(REPLACE(STUFF((SELECT ',' +
        (CASE WHEN [ID]=0 THEN CONVERT(NVARCHAR(1),(SUBSTRING(NullBytes, n, 1) % 2))  ELSE CONVERT(NVARCHAR(1),((SUBSTRING(NullBytes, n, 1) / [Bitvalue]) % 2)) END) --as [nullBitMap]
FROM
N4 AS Nums
Join RowData AS C ON n<=NullBitMapLength
Cross Join @bitTable WHERE C.[RowLogContents]=D.[RowLogContents] ORDER BY [RowLogContents],n ASC FOR XML PATH('')),1,1,''),',',''))
FROM RowData D

CREATE TABLE [#temp_Data]
(
    [FieldName]  VARCHAR(MAX) COLLATE database_default NOT NULL,
    [FieldValue] VARCHAR(MAX) COLLATE database_default NOT NULL,
    [Rowlogcontents] VARBINARY(8000),
    [Transaction ID] VARCHAR(MAX) COLLATE database_default NOT NULL,
    [Slot ID] int
)
---Create common table expression and join it with the rowdata table
--to get each column details
;With CTE AS (
/*This part is for variable data columns*/
SELECT Rowlogcontents,
[Transaction ID],
[Slot ID],
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,
--Calculate the variable column size from the variable column offset array
(CASE WHEN leaf_offset<1 and SUBSTRING([nullBitMap], cols.leaf_null_bit, 1)=0 THEN
CONVERT(SMALLINT, CONVERT(BINARY(2), REVERSE (SUBSTRING ([ColumnOffsetArray], (2 * leaf_offset*-1) - 1, 2)))) ELSE 0 END) AS [Column value Size],

---Calculate the column length
(CASE WHEN leaf_offset<1 and SUBSTRING([nullBitMap], cols.leaf_null_bit, 1)=0 THEN  CONVERT(SMALLINT, CONVERT(BINARY(2), REVERSE (SUBSTRING ([ColumnOffsetArray], (2 * (leaf_offset*-1)) - 1, 2))))
- ISNULL(NULLIF(CONVERT(SMALLINT, CONVERT(BINARY(2), REVERSE (SUBSTRING ([ColumnOffsetArray], (2 * ((leaf_offset*-1) - 1)) - 1, 2)))), 0), [varColumnStart])
ELSE 0 END) AS [Column Length]

--Get the Hexa decimal value from the RowlogContent
--HexValue of the variable column=Substring([Column value Size] - [Column Length] + 1,[Column Length])
--This is the data of your column but in the Hexvalue
,CASE WHEN SUBSTRING([nullBitMap], cols.leaf_null_bit, 1)=1 THEN NULL ELSE
SUBSTRING(Rowlogcontents,((CASE WHEN leaf_offset<1 and SUBSTRING([nullBitMap], cols.leaf_null_bit, 1)=0 THEN CONVERT(SMALLINT, CONVERT(BINARY(2), REVERSE (SUBSTRING ([ColumnOffsetArray], (2 * leaf_offset*-1) - 1, 2)))) ELSE 0 END)
- ((CASE WHEN leaf_offset<1 and SUBSTRING([nullBitMap], cols.leaf_null_bit, 1)=0 THEN  CONVERT(SMALLINT, CONVERT(BINARY(2), REVERSE (SUBSTRING ([ColumnOffsetArray], (2 * (leaf_offset*-1)) - 1, 2))))
- ISNULL(NULLIF(CONVERT(SMALLINT, CONVERT(BINARY(2), REVERSE (SUBSTRING ([ColumnOffsetArray], (2 * ((leaf_offset*-1) - 1)) - 1, 2)))), 0), [varColumnStart])
ELSE 0 END))) + 1,((CASE WHEN leaf_offset<1 and SUBSTRING([nullBitMap], cols.leaf_null_bit, 1)=0 THEN  CONVERT(SMALLINT, CONVERT(BINARY(2), REVERSE (SUBSTRING ([ColumnOffsetArray], (2 * (leaf_offset*-1)) - 1, 2))))
- ISNULL(NULLIF(CONVERT(SMALLINT, CONVERT(BINARY(2), REVERSE (SUBSTRING ([ColumnOffsetArray], (2 * ((leaf_offset*-1) - 1)) - 1, 2)))), 0), [varColumnStart])
ELSE 0 END))) END AS hex_Value

FROM @DeletedRecords A
Inner Join sys.allocation_units allocunits On A.[AllocUnitId]=allocunits.[Allocation_Unit_Id]
INNER JOIN sys.partitions partitions ON (allocunits.type IN (1, 3)
AND partitions.hobt_id = allocunits.container_id) OR (allocunits.type = 2 AND partitions.partition_id = allocunits.container_id)
INNER JOIN sys.system_internals_partition_columns cols ON cols.partition_id = partitions.partition_id
LEFT OUTER JOIN syscolumns ON syscolumns.id = partitions.object_id AND syscolumns.colid = cols.partition_column_id
WHERE leaf_offset<0

UNION
/*This part is for fixed data columns*/
SELECT  Rowlogcontents,
[Transaction ID],
[Slot ID],
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,
(SELECT TOP 1 ISNULL(SUM(CASE WHEN C.leaf_offset >1 THEN max_length ELSE 0 END),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 AS [Column value Size],
syscolumns.length AS [Column Length]

,CASE WHEN SUBSTRING([nullBitMap], cols.leaf_null_bit, 1)=1 THEN NULL ELSE
SUBSTRING
(
Rowlogcontents,(SELECT TOP 1 ISNULL(SUM(CASE WHEN C.leaf_offset >1 THEN max_length ELSE 0 END),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) END AS hex_Value
FROM @DeletedRecords A
Inner Join sys.allocation_units allocunits ON A.[AllocUnitId]=allocunits.[Allocation_Unit_Id]
INNER JOIN sys.partitions partitions ON (allocunits.type IN (1, 3)
 AND partitions.hobt_id = allocunits.container_id) OR (allocunits.type = 2 AND partitions.partition_id = allocunits.container_id)
INNER JOIN sys.system_internals_partition_columns cols ON cols.partition_id = partitions.partition_id
LEFT OUTER JOIN syscolumns ON syscolumns.id = partitions.object_id AND syscolumns.colid = cols.partition_column_id
WHERE leaf_offset>0 )

--Converting data from Hexvalue to its orgional datatype.
--Implemented datatype conversion mechanism for each datatype
--Select * from sys.columns Where [object_id]=object_id('' + @SchemaName_n_TableName + '')

INSERT INTO #temp_Data
SELECT NAME,
CASE
 WHEN system_type_id IN (231, 239) THEN  LTRIM(RTRIM(CONVERT(NVARCHAR(max),hex_Value)))  --NVARCHAR ,NCHAR
 WHEN system_type_id IN (167,175) THEN  LTRIM(RTRIM(CONVERT(VARCHAR(max),REPLACE(hex_Value, 0x00, 0x20))))  --VARCHAR,CHAR
 WHEN system_type_id = 48 THEN CONVERT(VARCHAR(MAX), CONVERT(TINYINT, CONVERT(BINARY(1), REVERSE (hex_Value)))) --TINY INTEGER
 WHEN system_type_id = 52 THEN CONVERT(VARCHAR(MAX), CONVERT(SMALLINT, CONVERT(BINARY(2), REVERSE (hex_Value)))) --SMALL INTEGER
 WHEN system_type_id = 56 THEN CONVERT(VARCHAR(MAX), CONVERT(INT, CONVERT(BINARY(4), REVERSE(hex_Value)))) -- INTEGER
 WHEN system_type_id = 127 THEN CONVERT(VARCHAR(MAX), CONVERT(BIGINT, CONVERT(BINARY(8), REVERSE(hex_Value))))-- BIG INTEGER
 WHEN system_type_id = 61 Then CONVERT(VARCHAR(MAX),CONVERT(DATETIME,CONVERT(VARBINARY(8000),REVERSE (hex_Value))),100) --DATETIME
 WHEN system_type_id =58 Then CONVERT(VARCHAR(MAX),CONVERT(SMALLDATETIME,CONVERT(VARBINARY(8000),REVERSE(hex_Value))),100) --SMALL DATETIME
 WHEN system_type_id = 108 THEN CONVERT(VARCHAR(MAX),CONVERT(NUMERIC(38,20), CONVERT(VARBINARY,CONVERT(VARBINARY(1),xprec)+CONVERT(VARBINARY(1),xscale))+CONVERT(VARBINARY(1),0) + hex_Value)) --- NUMERIC  
 WHEN system_type_id In(60,122) THEN CONVERT(VARCHAR(MAX),Convert(MONEY,Convert(VARBINARY(8000),Reverse(hex_Value))),2) --MONEY,SMALLMONEY
 --WHEN system_type_id =106 THEN CONVERT(VARCHAR(MAX), CAST(CONVERT(Decimal(38,34), CONVERT(VARBINARY,Convert(VARBINARY,xprec)+CONVERT(VARBINARY,xscale))+CONVERT(VARBINARY(1),0) + hex_Value) as FLOAT)) --- DECIMAL
 WHEN system_type_id =106 And xscale=1 THEN CONVERT(VARCHAR(MAX), CAST(CONVERT(Decimal(38,34), CONVERT(VARBINARY,Convert(VARBINARY,xprec)+CONVERT(VARBINARY,xscale))+CONVERT(VARBINARY(1),0) + hex_Value) as FLOAT)) --— DECIMAL

When system_type_id =106 And xscale=0 THEN CONVERT(VARCHAR(MAX),CONVERT(bigINT,CONVERT(BINARY(8), REVERSE(hex_Value))))
 WHEN system_type_id = 104 THEN CONVERT(VARCHAR(MAX),CONVERT (BIT,CONVERT(BINARY(1), hex_Value)%2))  -- BIT
 WHEN system_type_id =62 THEN  RTRIM(LTRIM(STR(CONVERT(FLOAT,SIGN(CAST(CONVERT(VARBINARY(8000),Reverse(hex_Value)) AS BIGINT)) * (1.0 + (CAST(CONVERT(VARBINARY(8000),Reverse(hex_Value)) AS BIGINT) & 0x000FFFFFFFFFFFFF) * POWER(CAST(2 AS FLOAT), -52)) * POWER(CAST(2 AS FLOAT),((CAST(CONVERT(VARBINARY(8000),Reverse(hex_Value)) AS BIGINT) & 0x7ff0000000000000) / EXP(52 * LOG(2))-1023))),53,LEN(hex_Value)))) --- FLOAT
 When system_type_id =59 THEN  Left(LTRIM(STR(CAST(SIGN(CAST(Convert(VARBINARY(8000),REVERSE(hex_Value)) AS BIGINT))* (1.0 + (CAST(CONVERT(VARBINARY(8000),Reverse(hex_Value)) AS BIGINT) & 0x007FFFFF) * POWER(CAST(2 AS Real), -23)) * POWER(CAST(2 AS Real),(((CAST(CONVERT(VARBINARY(8000),Reverse(hex_Value)) AS INT) )& 0x7f800000)/ EXP(23 * LOG(2))-127))AS REAL),23,23)),8) --Real
 WHEN system_type_id In (165,173) THEN (CASE WHEN CHARINDEX(0x,cast('' AS XML).value('xs:hexBinary(sql:column("hex_Value"))', 'VARBINARY(8000)')) = 0 THEN '0x' ELSE '' END) +cast('' AS XML).value('xs:hexBinary(sql:column("hex_Value"))', 'varchar(max)') -- BINARY,VARBINARY
 WHEN system_type_id =36 THEN CONVERT(VARCHAR(MAX),CONVERT(UNIQUEIDENTIFIER,hex_Value)) --UNIQUEIDENTIFIER
 END AS FieldValue
,[Rowlogcontents]
,[Transaction ID]
,[Slot ID]
FROM CTE ORDER BY nullbit

--Create the column name in the same order to do pivot table.

DECLARE @FieldName VARCHAR(max)
SET @FieldName = STUFF(
(
SELECT ',' + CAST(QUOTENAME([Name]) AS VARCHAR(MAX)) FROM syscolumns WHERE id=object_id('' + @SchemaName_n_TableName + '')

FOR XML PATH('')
), 1, 1, '')

--Finally did pivot table and got the data back in the same format.
--The [Update Statement] column will give you the query that you can execute in case of recovery.
SET @sql = 'SELECT ' + @FieldName  + ' FROM #temp_Data 
PIVOT (Min([FieldValue]) FOR FieldName IN (' + @FieldName  + ')) AS pvt
ORDER BY Convert(int,[Transaction ID],Convert(int,[Slot ID]))'

EXEC sp_executesql @sql

GO
SQL Server
SQL Server
A family of Microsoft relational database management and analysis systems for e-commerce, line-of-business, and data warehousing solutions.
12,654 questions
Transact-SQL
Transact-SQL
A Microsoft extension to the ANSI SQL language that includes procedural programming, local variables, and various support functions.
4,551 questions

5 answers

Sort by: Most helpful
Most helpful Newest Oldest
  1. Erland Sommarskog 100.8K Reputation points MVP
    2021-04-10T09:13:11.677+00:00

    I will make one more comment on this thread, which is more of a meta-comment.

    Ahmed dumped 400 lines of procedure code without actually explaining what he wanted to achieve. This cause a lot of confusion, because no one actually starts reading 400 lines of code, but we simply look at the lines addressed in the error message. Keep in mind that people who answer questions here do so in our free time, and we don't spend hours on a single question. In fact, we may not always spend ten minutes.

    Ahmed started a new thread with the same problem with a little more clues, and this time I noticed that the code is calling sys.fn_dblog(). It seems that Ahmed is trying to recover a table through the transaction log. (In the other thread, I have pointed out that this is a lost case.) It also seems that Ahmed did not write this code himself, but found it somewhere.

    This thread would have been a lot short and lot less frustrating if Ahmed had started his post something like:

    I have mistakenly truncated a table, and I found this procedure in this blog post (link goes here), which claims to be table to recover the data, but it errors out with this error message.

    1 person found this answer helpful.
    0 comments
  2. Erland Sommarskog 100.8K Reputation points MVP
    2021-04-08T21:35:04.927+00:00

    You are doing a lot of substring with charindex on that line. I would guess that the data does not look like you expect it to. For instance, maybe the strings Slot and Offset does not appear you intended.

    You will need to add some debug code to see what you have. Once you have assembled some test data that exhibits the problem, it be worth asking for help here if you can't figure out a good solution.

    But to be blunt, it is not very useful to dump a 400-line long stored procedure, but not supplying any sample data.

  3. ahmed salah 3,216 Reputation points
    2021-04-08T22:49:55.877+00:00

    1- first point table script and insert as above

    CREATE TABLE [dbo].[Student](  
      [Sno] [int] NOT NULL,  
      [Student ID] nvarchar(6) Not NULL ,  
      [Student name] [varchar](50) NOT NULL,  
      [Date of Birth]  datetime not null,  
      [Weight] [int] NULL)  
--Insert data into table
Insert into dbo.[Student] values (1,'STD001','Bob','2003-12-31',40)  
Insert into dbo.[Student] values (2,'STD002','Alexander','2004-11-15',35)

    2- i need to get data truncate from table dbo.student
    after make truncate table student
    how to get two rows truncated
    3- desired output get data after truncate so i need to get
    out put result

    Sno Student ID  Student name    Date of Birth   Weight
1   STD001  Bob 2003-12-31 00:00:00.000 40
2   STD002  Alexander   2004-11-15 00:00:00.000 35
  4. EchoLiu-MSFT 14,571 Reputation points
    2021-04-09T03:09:06.26+00:00 
     SELECT [Page ID],Substring([ParentObject],CHARINDEX('Slot', [ParentObject])+4, (CHARINDEX('Offset', [ParentObject])-(CHARINDEX('Slot', [ParentObject])+4)) ) as [Slot ID]

    Not sure if the problem lies in this statement. But the reason for the error may be that the result of the following statement is negative.If length is negative, an error is generated and the statement is terminated: 

        (CHARINDEX('Offset', [ParentObject])-(CHARINDEX('Slot', [ParentObject])+4))

    When the result of the above statement is negative, what kind of result do you want the substring function to return?

    The following statement may make your code work, but it may not be the result you expect: 

    SELECT [Page ID],
Substring([ParentObject],CHARINDEX('Slot', [ParentObject])+4, ABS(CHARINDEX('Offset', [ParentObject])-(CHARINDEX('Slot', [ParentObject])+4))) ) as [Slot ID]

    Regards
    Echo

    If the answer is helpful, please click "Accept Answer" and upvote it.

  5. EchoLiu-MSFT 14,571 Reputation points
    2021-04-12T08:52:40.073+00:00

    For such problems, maybe you can solve the problem faster by publishing the original purpose and requirements.

    Echo

    0 comments