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Comment créer des vues d'historique OU d'audit à partir de tables de capture de données modifiées (CDC) dans SQL Server - Tutoriel SQL Server

Scénario :

Vous travaillez en tant que DBA ou développeur SQL Server, vous avez activé Change Data Capture sur l'une des bases de données SQL Server. Après avoir activé CDC, vous souhaitez créer des vues AUDIT OU HIST afin d'obtenir les enregistrements modifiés.

Solution :

Le script ci-dessous créera une vue pour chacune des tables sur lesquelles CDC est activé dans votre base de données. J'ai utilisé le schéma d'audit, avant d'exécuter le script, vous devez créer un schéma d'audit ou si vous souhaitez créer des vues dans le schéma hist, puis modifiez Schema in Below Code from Audit To Hist.
Chaque vue nous renverra sous les colonnes
  • Commit_Time,
  • Colum_Name,
  • Ancienne_Valeur
  • Nouvelle_Valeur,
  • Modifié par




IF OBJECT_ID(N'tempdb..##CDC_TableList') IS NOT NULL
BEGIN
    DROP TABLE ##CDC_TableList
END

SELECT T.name AS TableName,
       C.name AS ColumnName,
       'CASE WHEN (sys.Fn_cdc_is_bit_set (sys.Fn_cdc_get_column_ordinal (''dbo_'
       + T.name + ''',''' + C.name+
       + '''),__$update_mask) = 1) THEN Cast('
       + C.Name
       + ' AS SQL_VARIANT) ELSE NULL END AS '
       + C.name  AS CaseStm INTO ##CDC_TableList
 FROM   sys.tables T
       INNER JOIN sys.columns c
               ON T.OBJECT_ID = c.OBJECT_ID
WHERE  is_tracked_by_cdc = 1
       AND c.is_identity = 0
       AND C.name NOT IN ( 'CreatedBy', 'CreatedDate', 'ModifiedBy', 'ModifiedDate' )
       AND T.TYPE='U'
       AND T.is_ms_shipped<>1
      
      -- Select * from sys.tables

DECLARE @TableName NVARCHAR(200)
DECLARE cdc_cursor CURSOR FOR 
SELECT DISTINCT TableName FROM ##CDC_TableList
OPEN cdc_cursor 
FETCH NEXT FROM cdc_cursor INTO @TableName

WHILE @@FETCH_STATUS = 0 
BEGIN

DECLARE @ColumnList  NVARCHAR(MAX)
DECLARE @CaseStmList NVARCHAR(MAX)
DECLARE @SQL_Stm  NVARCHAR(MAX)
DECLARE @SQL_Stm_DropView  NVARCHAR(MAX)
PRINT @TableName

 SELECT @ColumnList = STUFF(o.COLUMNNAME, 1, 1, '')
 FROM ##CDC_TableList t CROSS APPLY  (SELECT ',' + ColumnName+CHAR(10) AS [text()]
            FROM  ##CDC_TableList c
            WHERE    c.TableName = t.TableName
            FOR XML PATH('')) o (COLUMNNAME)
 WHERE t.TableName=@TableName
 PRINT @ColumnList
 
 SELECT @CaseStmList = STUFF(o.COLUMNNAME, 1, 1, '')
 FROM ##CDC_TableList t CROSS APPLY  (SELECT ',' + CaseStm+CHAR(10) AS [text()]
            FROM  ##CDC_TableList c
            WHERE    c.TableName = t.TableName
            FOR XML PATH('')) o (COLUMNNAME)
 WHERE t.TableName=@TableName
 --PRINT @CaseStmList


--If using Other Schema than AUDIT THEN change to that.
SET @SQL_Stm=' CREATE VIEW AUDIT.vw_'+@TableName+' AS

SELECT sys.Fn_cdc_map_lsn_to_time(up_b.__$start_lsn) AS Commit_Time, up_b.Column_Name, up_b.Old_Value, up_a.New_Value,up_a.ModifiedBy
FROM
    ( SELECT __$start_lsn, column_name, old_value,ModifiedBy
   FROM (SELECT __$start_lsn,'+@CaseStmList+',ModifiedBy FROM cdc.fn_cdc_get_all_changes_dbo_'+@TableName+'( sys.fn_cdc_get_min_lsn(''dbo_'+@TableName+'''), sys.fn_cdc_map_time_to_lsn(''largest less than or equal'',GETDATE()), N''all update old'')
 WHERE __$operation = 3
  ) AS BeforeUpdate
  UNPIVOT (old_value FOR column_name IN ('+@ColumnList+') ) AS unp) AS up_b INNER JOIN
  (SELECT __$start_lsn, column_name, new_value,ModifiedBy
   FROM (SELECT __$start_lsn,'+@CaseStmList+',ModifiedBy FROM cdc.fn_cdc_get_all_changes_dbo_'+@TableName+'(sys.fn_cdc_get_min_lsn(''dbo_'+@TableName+'''), sys.fn_cdc_map_time_to_lsn(''largest less than or equal'',GETDATE()), N''all'')
    WHERE __$operation = 4
   ) AS AfterUpdate
   UNPIVOT (new_value FOR column_name IN ('+@ColumnList+') ) AS unp ) AS up_a
ON up_b.__$start_lsn = up_a.__$start_lsn AND up_b.column_name = up_a.column_name'
--Drop View if already exists
SET @SQL_Stm_DropView= 'IF EXISTS (SELECT TABLE_NAME FROM INFORMATION_SCHEMA.VIEWS
         WHERE TABLE_NAME = ''vw_'+@TableName+''')
   DROP VIEW AUDIT.vw_'+@TableName
   PRINT @SQL_Stm_DropView

EXEC (@SQL_Stm_DropView)
EXEC ( @SQL_Stm)
FETCH NEXT FROM cdc_cursor INTO @TableName
END 

CLOSE cdc_cursor 
DEALLOCATE cdc_cursor