最终,我实现的框架每个表使用三个触发器,这些触发器基于表的更改插入审核信息。
我的插入和删除审核触发器非常简单。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在审核控制之下,然后根据“插入”和“已删除”列中的列值是否相等执行插入操作,因为我不想写不必要的审核记录。最终,我想知道是否有一种编写存储过程的方法,该方法允许我动态执行下面的insert语句,从而减少触发器中的代码量。基本上,我预想触发器将使用受审计控制的每个列名来触发sproc,然后存储过程将使用该列名来执行以下代码段。目前,
建议的更改后修订触发器
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
如何访问#results?我必须使用游标吗?
我们已通过以下方式解决了该问题。
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
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