如何创建通用SQL Server存储过程以基于插入和删除的触发器执行插入审计表

Question

我已根据以下帖子的第一个答案提供的信息实施了审计跟踪框架:

SQL Server历史记录表 - 通过SP或Trigger填充？

最终,我实现的框架使用每个表三个触发器,根据表的更改插入审计信息.

我的插入和删除审计触发器非常简单.但是,更新触发器要复杂得多,因为触发器必须检查以确定每个列是否处于审计控制之下,然后根据Inserted和Deleted列中的列值是否相等来执行插入操作.我不想写不必要的审计记录.最后,我想知道是否有办法编写一个存储过程,通过允许我动态执行下面的insert语句来减少触发器中的代码量.基本上,我设想触发器使用处于审计控制下的每个列名触发sproc,然后存储过程将使用列名来执行下面的代码片段.目前,对于审计控制下的每一列,我都有以下代码,遗憾的是,这会产生大量冗余代码.

建议更改后修改触发器

CREATE TRIGGER [dbo].[Audit_Customers_Update] ON [dbo].[Customers]
FOR UPDATE AS

select FirstName,LastName into #deleted from deleted;

declare /*const*/ @TABLE_NAME sysname = '[table name]';

declare f cursor
local
forward_only
read_only
for
  select c.name, quotename(c.name, '[')
  from
    sys.columns c
    inner join sys.types t on c.system_type_id = t.system_type_id
  where
    c.object_id = object_id(@TABLE_NAME)
    and c.is_computed = 0
    and c.is_identity = 0
    and t.name not in ('text', 'image', 'timestamp', 'xml')
    and (substring(COLUMNS_UPDATED(), ((c.column_id - 1) / 8) + 1, 1) & power(2, (c.column_id - 1) % 8)) > 0
  ;

declare @field_name sysname, @field_name_sanitised sysname;
create table #results (row_id int not null,
                       field_name sysname not null,
                       oldval nvarchar(150) null,
                       newval nvarchar(150) null);

-- For each changed field, insert what exactly changed into #results

open f;

fetch next from f into @field_name, @field_name_sanitised;
while @@fetch_status = 0
begin
  declare @query nvarchar(4000);

  set @query =  N'insert into #results(row_id, field_name, oldval, newval)
                  select d.row_id, @field_name, d.' + @field_name_sanitised + N', i.' + @field_name_sanitised + N'
                  from
                    #deleted d inner join ' + @TABLE_NAME + N' i on d.row_id = i.row_id
                  where
                    (d.' + @field_name_sanitised + N' <> i.' + @field_name_sanitised + N')
                    or
                    (case when d.' + @field_name_sanitised + N' is null then 1 else 0 end <> case when i.' + @field_name_sanitised + N' is null then 1 else 0 end);'
                ;    

  exec sp_executesql
    @stmt = @query,
    @params = N'@field_name sysname',
    @field_name = @field_name
  ;

  fetch next from f into @field_name, @field_name_sanitised;
end;

close f;
deallocate f;

-- Do something meaningful to #results here

我如何访问#results？我必须使用光标吗？

Answer 1

我们通过以下方式解决了这个问题.

select <list of tracked columns here> into #deleted from deleted;

declare /*const*/ @TABLE_NAME sysname = '[table name]';

declare f cursor
local
forward_only
read_only
for
  select c.name, quotename(c.name, '[')
  from
    sys.columns c
    inner join sys.types t on c.system_type_id = t.system_type_id
  where
    c.object_id = object_id(@TABLE_NAME)
    and c.is_computed = 0
    and c.is_identity = 0
    and t.name not in ('text', 'image', 'timestamp', 'xml')
    and (substring(COLUMNS_UPDATED(), ((c.column_id - 1) / 8) + 1, 1) & power(2, (c.column_id - 1) % 8)) > 0
  ;

declare @field_name sysname, @field_name_sanitised sysname;
create table #results (row_id int not null, field_name sysname not null, oldval nvarchar(150) null, newval nvarchar(150) null);

-- For each changed field, insert what exactly changed into #results

open f;

fetch next from f into @field_name, @field_name_sanitised;
while @@fetch_status = 0
begin
  declare @query nvarchar(4000);

  set @query =  N'insert into #results(row_id, field_name, oldval, newval)
                  select d.row_id, @field_name, d.' + @field_name_sanitised + N', i.' + @field_name_sanitised + N'
                  from
                    #deleted d inner join ' + @TABLE_NAME + N' i on d.row_id = i.row_id
                  where
                    (d.' + @field_name_sanitised + N' <> i.' + @field_name_sanitised + N')
                    or
                    (case when d.' + @field_name_sanitised + N' is null then 1 else 0 end <> case when i.' + @field_name_sanitised + N' is null then 1 else 0 end);'
                ;    

  exec sp_executesql
    @stmt = @query,
    @params = N'@field_name sysname',
    @field_name = @field_name
  ;

  fetch next from f into @field_name, @field_name_sanitised;
end;

close f;
deallocate f;

-- Do something meaningful to #results here

相关阅读:

• COLUMNS_UPDATED
• SYS.COLUMNS