SQL Server 添加Delete操作回滚日志方式

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SQL Server 添加Delete操作回滚日志方式

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我们在操作表的时候难免会遇到误删除，或者删掉的数据还想恢复的情况。

也许细心的朋友会用begin tran rollback/commit 这种事务来避免出现失误，但这并不是最保险的。

如果提交了事物发现删错了或者忘记提交从而导致表被锁，这些问题总是不可避免的。

废话不多说了，下面直接进入正题，通过触发器记录删除日志，避免误删除带来的尴尬。

下面这段sql粘过去直接运行，建立一个存储过程：

CREATE PROCEDURE [dbo].[SP_DELETE_LOG]

@TABLENAME VARCHAR(50)

AS

BEGIN

SET NOCOUNT ON;

IF NOT EXISTS(SELECT * FROM sys.tables WHERE NAME = @TABLENAME AND TYPE = 'U' )

BEGIN

PRINT'ERROR：not exist table '+@TABLENAME

RETURN

END

IF (@TABLENAME LIKE'BACKUP_%' OR @TABLENAME='UPDATE_LOG' )

BEGIN

--PRINT'ERROR：not exist table '+@TABLENAME

RETURN

END

--================================判断是否存在 UPDATE_LOG 表============================

IF NOT EXISTS(SELECT * FROM sys.tables WHERE NAME = 'UPDATE_LOG' AND TYPE = 'U')

CREATE TABLE UPDATE_LOG

(

UpdateGUID VARCHAR(36),

UpdateTime DATETIME,

TableName varchar(20),

UpdateType varchar(6),

RollBackSQL varchar(1000)

)

--=================================判断是否存在 BACKUP_ 表================================

IF NOT EXISTS(SELECT * FROM sys.tables WHERE NAME = 'BACKUP_'+@TABLENAME AND TYPE = 'U')

BEGIN

--DECLARE @SQL VARCHAR(500)

--SET @SQL='SELECT TOP 1 NEWID() AS [UpdateGUID],* INTO BACKUP_'+@TABLENAME+' FROM '+ @TABLENAME+'

-- DELETE FROM BACKUP_'+@TABLENAME

--SELECT @SQL

--EXEC(@SQL)

DECLARE test_Cursor CURSOR FOR

SELECT COLUMN_NAME,DATA_TYPE,CHARACTER_MAXIMUM_LENGTH FROM INFORMATION_SCHEMA.columns

WHERE TABLE_NAME=@TABLENAME

OPEN test_Cursor

DECLARE @SQLTB NVARCHAR(MAX)=''

DECLARE @COLUMN_NAME NVARCHAR(50),@DATA_TYPE VARCHAR(20),@CHARACTER_MAXIMUM_LENGTH INT

FETCH NEXT FROM test_Cursor INTO @COLUMN_NAME,@DATA_TYPE,@CHARACTER_MAXIMUM_LENGTH

WHILE @@FETCH_STATUS=0

BEGIN

SET @SQLTB=@SQLTB+'['+@COLUMN_NAME+'] '+@DATA_TYPE+CASE ISNULL(@CHARACTER_MAXIMUM_LENGTH,0) WHEN 0 THEN '' WHEN -1 THEN '(MAX)' ELSE'('+CAST(@CHARACTER_MAXIMUM_LENGTH AS VARCHAR(10))+')' END+','

FETCH NEXT FROM test_Cursor INTO @COLUMN_NAME,@DATA_TYPE,@CHARACTER_MAXIMUM_LENGTH

END

SET @SQLTB='CREATE TABLE BACKUP_'+@TABLENAME+' (UpdateGUID varchar(36),'+SUBSTRING(@SQLTB,1,LEN(@SQLTB)-1)+')'

EXEC (@SQLTB)

CLOSE test_Cursor

DEALLOCATE test_Cursor

END

--======================================判断是否存在 DELETE 触发器=========================

IF NOT EXISTS(SELECT * FROM sys.objects WHERE NAME = 'tg_'+@TABLENAME+'_Delete' AND TYPE = 'TR')

BEGIN

DECLARE @SQLTR NVARCHAR(MAX)

SET @SQLTR='

CREATE TRIGGER tg_'+@TABLENAME+'_Delete

ON '+@TABLENAME+'

AFTER delete

AS

BEGIN

SET NOCOUNT ON;

--==============================获取GUID==========================================

DECLARE @NEWID VARCHAR(36)=NEWID()

--==============================将删掉的数据插入备份表============================

INSERT INTO [dbo].[BACKUP_'+@TABLENAME+']

SELECT @NEWID,* FROM deleted

--==============================记录日志和回滚操作的SQL===========================

--*********************生成列名**********************

DECLARE @COLUMN NVARCHAR(MAX)=''''

SELECT @COLUMN+='',[''+COLUMN_NAME+'']'' FROM INFORMATION_SCHEMA.columns

WHERE TABLE_NAME='''+@TABLENAME+'''

AND COLUMNPROPERTY(OBJECT_ID('''+@TABLENAME+'''),COLUMN_NAME,''IsIdentity'')<>1 --非自增字段

SET @COLUMN=SUBSTRING(@COLUMN,2,LEN(@COLUMN))

INSERT INTO [dbo].[UPDATE_LOG]

SELECT @NEWID,GETDATE(),'''+@TABLENAME+''',''DELETE'',''INSERT INTO '+@TABLENAME+' SELECT ''+@COLUMN+'' FROM BACKUP_'+@TABLENAME+' WHERE UPDATEGUID=''''''+@NEWID+''''''''