通过触发器实现记录数据的修改日志

1、先为数据库建立一个字段试图，所有数据都是从系统表中提取，便于以后用户可以扩展系统功能。

 

CREATE VIEW dbo.V_SystemColumn
AS
SELECT DISTINCT 
      TOP 100 PERCENT dbo.sysobjects.name AS TableName, dbo.sysobjects.id, 
       dbo.sysobjects.xtype, dbo.syscolumns.name AS ColumnName, 
       dbo.syscolumns.colid, dbo.syscolumns.type, dbo.syscolumns.colstat
FROM dbo.sysobjects INNER JOIN
       dbo.syscolumns ON dbo.sysobjects.id = dbo.syscolumns.id
WHERE (dbo.sysobjects.xtype = 'U')
ORDER BY dbo.sysobjects.id, dbo.syscolumns.colid

 

 2、建立一个各个表之间关联的视图。

 

CREATE VIEW dbo.V_Reference
AS
SELECT DISTINCT 
      TOP 100 PERCENT o1.name AS PK_TABLE_NAME, c1.name AS PK_COLUMN_NAME, 
       o2.name AS FK_TABLE_NAME, c2.name AS FK_COLUMN_NAME
FROM dbo.sysobjects o1 INNER JOIN
       dbo.sysreferences r ON o1.id = r.rkeyid INNER JOIN
       dbo.syscolumns c1 ON o1.id = c1.id AND r.rkey1 = c1.colid INNER JOIN
       dbo.sysobjects o2 ON r.fkeyid = o2.id INNER JOIN
       dbo.syscolumns c2 ON o2.id = c2.id AND r.fkey1 = c2.colid INNER JOIN
       dbo.sysindexes i ON r.rkeyid = i.id AND r.rkeyindid = i.indid
WHERE (permissions(o1.id) <> 0) AND (permissions(o2.id) <> 0)
ORDER BY FK_Table_Name

 

 

3、创建一个存取过程，参数为：表名、列名、Insert.列名的值、返回参数

CREATE Procedure GetColumnValue
@FKTableName Varchar(128),
@FKColumnName Varchar(128),
@FKValue Varchar(8000),
@ReturnValue Varchar(8000) OUTPUT
AS
declare @PkTableName Varchar(128)
declare @PkColumnName Varchar(128)
declare @PkDescriptionName Varchar(128)

declare @SqlText Varchar(8000)
declare @ret varchar(8000)

--获取关联主表的表名和字段名
select @PkTableName=Pk_Table_Name,@PkColumnName=Pk_Column_Name from V_Reference
  Where FK_Table_Name=@FKTableName and 
         FK_Column_Name=@FKColumnName

if(@PkTableName is null)
begin
  Select @ReturnValue=@FKValue
  return 0
end
else
begin
  Select Top 1 @PkDescriptionName=ColumnName 
    from V_SystemColumn 
    Where TableName=@PkTableName and ColumnName like '%Name'


 Create Table #temp
   (PkDescriptionName Varchar(8000) )


  select @SqlText='   Insert Into #temp Select  '+@PkDescriptionName 
  select @SqlText=@SqlText+'    from '+@PkTableName
  select @SqlText=@SqlText+'   Where '+@PkColumnName+'='+''''+@FKValue+''''

  execute(@SqlText)

  select @ReturnValue=PkDescriptionName from #temp
end
GO

 4、为系统创建记录日志的表

CREATE TABLE T_SystemLog (
        TableName            varchar(128) NULL,
        KeyValue             varchar(20) NOT NULL,
        FieldName            varchar(128) NULL,
        OldValue             varchar(8000) NULL,
        NewValue             varchar(8000) NULL,
        Modifier             varchar(20) NULL,
        ModifyDate           datetime NULL DEFAULT CURRENT_TIMESTAMP
)
go

 5、创建日志记录存取过程

CREATE Procedure Logger
@TableName Varchar(128),
@ColumnName Varchar(128),
@KeyValue int,
@OldValue Varchar(8000),
@NewValue Varchar(8000),
@LastModifier Varchar(20)
AS
if(@OldValue<>@NewValue)
begin
  exec GetColumnValue @TableName,@ColumnName,@OldValue,@OldValue Output 
  exec GetColumnValue @TableName,@ColumnName,@NewValue,@NewValue Output
  Insert Into T_SystemLog(TableName,KeyValue,FieldName,OldValue,NewValue,Modifier,ModifyDate)
    Values( @TableName,@KeyValue,@ColumnName,@OldValue,@NewValue,@LastModifier,getdate())
end
GO

 6、为需要记录修改日志的表创建Insert、Update触发器

CREATE trigger uti_corp on T_Corp
for Update
AS
set nocount on
declare @KeyValue int
declare @OldValue Varchar(8000)
declare @NewValue varchar(8000)
declare @LastModifier varchar(8000)

if(update(departmentid))
begin
  select @KeyValue=corpid,@NewValue=departmentid,@LastModifier=LastModifier from inserted
  select @OldValue=departmentid from deleted
  execute Logger 'T_Corp','DepartmentID',@KeyValue,@OldValue,@NewValue,@LastModifier
end