Tracking changes in a SQL server 2005 database

Question

I have been tasked with developing a solution that tracks changes to a database.

For updates I need to capture:

• date of update
• old value

Answer 1

A trigger wouldn't have all the information you need for a bunch of reasons - but no user id is the clincher.

I'd say you're on the right track with a common sp to insert wherever a change is made. If you're standardizing on sp's for your interfaces then you're ahead of the game - it will be hard to sneak in a change that isn't tracked.

Look at this as the equivalent of an audit trail in an accounting application - this is the Journal - a single table with every transaction recorded. They wouldn't implement separate journals for deposits, withdrawals, adjustments, etc. and this is the same principle.

Answer 2

I would suggest you to use 2 column's in every table. names rowhistory and IsDeleted and the data type will be xml and bit. Never delete the rows, always use flag IsDeleted Now go with update triggers. I will give you example for the same I have this one table called Page

    CREATE TABLE te_Page([Id] [int] IDENTITY(1,1) NOT NULL, [Name] [varchar](200) NOT NULL, [Description] [varchar](200) NULL,[CreatedBy] [uniqueidentifier] NULL, [CreatedDate] [datetime] NOT NULL, [UpdatedBy] [uniqueidentifier] NULL, [UpdatedDate] [datetime] NULL, [IsDeleted] [bit] NULL, [RowHistory] [xml] NULL, CONSTRAINT [PK_tm_Page] PRIMARY KEY CLUSTERED ([Id] ASC )WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY] ) ON [PRIMARY]

Now after creating the table all you need to do is copy paste the below code and your task is done for Page table. It will start recording the history of the row in the same row which is updated along with old and new values.

                ALTER Trigger [dbo].[Trg_Te_Page]    
        On [dbo].[te_Page]                
        After Update                
        As                 
        --If @@rowcount = 0 Or Update(RowHistory)    
        --Return    

        Declare @xml NVARCHAR(MAX)     
        Declare @currentxml NVARCHAR(MAX)   
        Declare @node NVARCHAR(MAX)    
        Declare @ishistoryexists XML    

        Declare @FormLineAttributeValueId int  

        -- new Values  
        Declare @new_Name varchar(200)  
        Declare @new_Description varchar(200)  

        Declare @new_CreatedBy UNIQUEIDENTIFIER    
        Declare @new_CreatedDate DATETIME    
        Declare @new_UpdatedBy UNIQUEIDENTIFIER    
        Declare @new_UpdatedDate DATETIME    
        Declare @new_IsDeleted BIT  

        --old values  
        Declare @old_Name varchar(200)  
        Declare @old_Description varchar(200)  

        Declare @old_CreatedBy UNIQUEIDENTIFIER    
        Declare @old_CreatedDate DATETIME    
        Declare @old_UpdatedBy UNIQUEIDENTIFIER    
        Declare @old_UpdatedDate DATETIME    
        Declare @old_IsDeleted BIT  


        -- declare temp fmId  
        Declare @fmId int  
        -- declare cursor  
        DECLARE curFormId cursor   
        FOR select Id from INSERTED   
        -- open cursor       
        OPEN curFormId  
        -- fetch row  
        FETCH NEXT FROM curFormId INTO @fmId  

        WHILE @@FETCH_STATUS  = 0   
        BEGIN   

        Select   
        @FormLineAttributeValueId = Id,   
        @old_Name = Name,  
        @old_Description = [Description],  

        @old_CreatedBy = CreatedBy,    
        @old_CreatedDate =CreatedDate,  
        @old_UpdatedBy =UpdatedBy,    
        @old_UpdatedDate =UpdatedDate,  
        @old_IsDeleted  = IsDeleted,  
        @currentxml = cast(RowHistory as NVARCHAR(MAX))  
        From DELETED where Id=@fmId  



        Select      
        @new_Name = Name,  
        @new_Description = [Description],  

        @new_CreatedBy = CreatedBy,    
        @new_CreatedDate =CreatedDate,  
        @new_UpdatedBy =UpdatedBy,    
        @new_UpdatedDate =UpdatedDate,  
        @new_IsDeleted  = IsDeleted  
        From INSERTED where Id=@fmId  

        set @old_Name = Replace(@old_Name,'&','&')
        set @old_Name = Replace(@old_Name,'>','>')  
        set @old_Name = Replace(@old_Name,'<','&lt;')     
        set @old_Name = Replace(@old_Name,'"','&quot;')
        set @old_Name = Replace(@old_Name,'''','&apos;')          

        set @new_Name = Replace(@new_Name,'&','&amp;')      
        set @new_Name = Replace(@new_Name,'>','&gt;')  
        set @new_Name = Replace(@new_Name,'<','&lt;')     
        set @new_Name = Replace(@new_Name,'"','&quot;')
        set @new_Name = Replace(@new_Name,'''','&apos;') 

        set @old_Description = Replace(@old_Description,'&','&amp;')
        set @old_Description = Replace(@old_Description,'>','&gt;')  
        set @old_Description = Replace(@old_Description,'<','&lt;')     
        set @old_Description = Replace(@old_Description,'"','&quot;')
        set @old_Description = Replace(@old_Description,'''','&apos;')          

        set @new_Description = Replace(@new_Description,'&','&amp;')      
        set @new_Description = Replace(@new_Description,'>','&gt;')  
        set @new_Description = Replace(@new_Description,'<','&lt;')     
        set @new_Description = Replace(@new_Description,'"','&quot;')
        set @new_Description = Replace(@new_Description,'''','&apos;')   

        set @xml = ''     

        BEGIN      

        -- for Name  
        If ltrim(rtrim(IsNull(@new_Name,''))) != ltrim(rtrim(IsNull(@old_Name,'')))    
        set @xml = @xml + '<ColumnInfo ColumnName="Name" OldValue="'+ @old_Name + '" NewValue="' + @new_Name + '"/>'    

        -- for Description  
        If ltrim(rtrim(IsNull(@new_Description,''))) != ltrim(rtrim(IsNull(@old_Description,'')))    
        set @xml = @xml + '<ColumnInfo ColumnName="Description" OldValue="'+ @old_Description + '" NewValue="' + @new_Description + '"/>'    

        -- CreatedDate     
        If IsNull(@new_CreatedDate,'') != IsNull(@old_CreatedDate,'')  
        set @xml = @xml + '<ColumnInfo ColumnName="CreatedDate" OldValue="'+ cast(isnull(@old_CreatedDate,'') as varchar(100)) + '" NewValue="' + cast(isnull(@new_CreatedDate,'') as varchar(100)) + '"/>'    

        -- CreatedBy     
        If cast(IsNull(@new_CreatedBy,'00000000-0000-0000-0000-000000000000')as varchar (36)) != cast(IsNull(@old_CreatedBy,'00000000-0000-0000-0000-000000000000')as varchar(36))    
        set @xml = @xml + '<ColumnInfo ColumnName="CreatedBy" OldValue="'+ cast(IsNull(@old_CreatedBy,'00000000-0000-0000-0000-000000000000') as varchar(36)) + '" NewValue="' + cast(isnull(@new_CreatedBy,'00000000-0000-0000-0000-000000000000') as varchar(36))+
        '"/>'    

        -- UpdatedDate       
        If IsNull(@new_UpdatedDate,'') != IsNull(@old_UpdatedDate,'')    
        set @xml = @xml + '<ColumnInfo ColumnName="UpdatedDate" OldValue="'+ cast(IsNull(@old_UpdatedDate,'') as varchar(100)) + '" NewValue="' + cast(IsNull(@new_UpdatedDate,'') as varchar(100)) + '"/>'    

        -- UpdatedBy     
        If cast(IsNull(@new_UpdatedBy,'00000000-0000-0000-0000-000000000000') as varchar(36)) != cast(IsNull(@old_UpdatedBy,'00000000-0000-0000-0000-000000000000') as varchar(36))    
        set @xml = @xml + '<ColumnInfo ColumnName="UpdatedBy" OldValue="'+ cast(IsNull(@old_UpdatedBy,'00000000-0000-0000-0000-000000000000') as varchar(36)) + '" NewValue="' + cast(IsNull(@new_UpdatedBy,'00000000-0000-0000-0000-000000000000') as varchar(36))+
        '"/>'    

        -- IsDeleted  
        If cast(IsNull(@new_IsDeleted,'') as varchar(10)) != cast(IsNull(@old_IsDeleted,'') as varchar(10))    
        set @xml = @xml + '<ColumnInfo ColumnName="IsDeleted" OldValue="'+ cast(IsNull(@old_IsDeleted,'') as varchar(10)) + '" NewValue="' + cast(IsNull(@new_IsDeleted,'') as varchar(10)) + '" />'    

        END    

        Set @xml = '<RowInfo TableName="te_Page" UpdatedBy="' + cast(IsNull(@new_UpdatedBy,'00000000-0000-0000-0000-000000000000') as varchar(50)) +  '" UpdatedDate="' + Convert(Varchar(20),GetDate()) + '">' + @xml + '</RowInfo>'    
        Select @ishistoryexists = RowHistory From DELETED     

        --print @ishistoryexists  


        If @ishistoryexists is null    
        Begin     
        Set @xml = '<History>' + @xml + '</History>'      
        Update te_Page    
        Set    
        RowHistory = @xml    
        Where     
        Id = @FormLineAttributeValueId    

        End    

        Else    
        Begin     
        set @xml = REPLACE(@currentxml, '<History>', '<History>' + @xml)  
        Update te_Page  
        Set  
        RowHistory = @xml  
        Where   
        Id = @FormLineAttributeValueId     
        End  


        FETCH NEXT FROM curFormId INTO @fmId  
        END   


        CLOSE curFormId  
        DEALLOCATE curFormId  

Now whenever you will perform any update your data will be stored in rowhistory column