sql server 2005中的DDL觸發(fā)器
SQL SERVER 2005中,新增加了許多新的特性,其中的DDL觸發(fā)器是個(gè)不錯(cuò)的選擇,根據(jù)資料初步學(xué)習(xí)如下,現(xiàn)整理之: 在sql server 2000中,只能為針對(duì)表發(fā)出的 DML 語(yǔ)句(INSERT、UPDATE 和 DELETE)定義 AFTER 觸發(fā)器。SQL Server 2005 可以就整個(gè)服務(wù)器或數(shù)據(jù)庫(kù)的某個(gè)范圍為 DDL 事件定義觸發(fā)器。可以為單個(gè) DDL 語(yǔ)句(例如,CREATE_TABLE)或者為一組語(yǔ)句(例如,DDL_DATABASE_LEVEL_EVENTS)定義 DDL 觸發(fā)器。在該觸發(fā)器內(nèi)部,您可以通過(guò)訪(fǎng)問(wèn) eventdata() 函數(shù)獲得與激發(fā)該觸發(fā)器的事件有關(guān)的數(shù)據(jù)。該函數(shù)返回有關(guān)事件的 XML 數(shù)據(jù)。每個(gè)事件的架構(gòu)都繼承了 Server Events 基礎(chǔ)架構(gòu)。 比如,在SQL SERVER 2005中,建立一個(gè)叫DDLTrTest 的數(shù)據(jù)庫(kù),并且建立一個(gè)叫mytable的表 和Usp_Querymytable 的存儲(chǔ)過(guò)程,如下所示 DROP DATABASE [DDLTRTEST] GO CREATE DATABASE DDLTRTEST GO USE [DDLTRTEST] GO IF; EXISTS (SELECT * FROM SYS.OBJECTS WHERE OBJECT_ID = OBJECT_ID(N'[DBO].[MYTABLE]') AND TYPE IN (N'U')) DROP TABLE [DBO].[MYTABLE] GO CREATE TABLE MYTABLE(ID INT, NAME VARCHAR(100)) GO INSERT INTO MYTABLE SELECT 1,'A' INSERT INTO MYTABLE SELECT 2,'B' INSERT INTO MYTABLE SELECT 3,'C' INSERT INTO MYTABLE SELECT 4,'D' INSERT INTO MYTABLE SELECT 5,'E' INSERT INTO MYTABLE SELECT 6,'F' GO USE [DDLTrTest] GO IF; EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[usp_querymytable]') AND type in (N'P', N'PC')) DROP PROCEDURE [dbo].[usp_querymytable] GO CREATE PROC USP_QUERYMYTABLE AS SELECT * FROM MYTABLE GO
接下來(lái)定義一個(gè)DDL觸發(fā)器如下 CREATE TRIGGER STOP_DDL_on_Table_and_PROCON DATABASE FOR CREATE_TABLE,DROP_TABLE, ALTER_TABLE,CREATE_PROCEDURE, ALTER_PROCEDURE,DROP_PROCEDUREAS SELECT EVENTDATA().value ('(/EVENT_INSTANCE/TSQLCommand/CommandText)[1]', 'nvarchar(max)')PRINT 'You are not allowed to CREATE,ALTER and DROP any Tables and Procedures' ROLLBACK;
接下來(lái),我們嘗試如下的操作: ALTER TABLE MYTABLE ADD X INT 結(jié)果如下,出現(xiàn)錯(cuò)誤提示 ALTER TABLE MYTABLE ADD X INT (1 row(s) affected) You are not allowed to CREATE,ALTER and DROP any Tables and Procedures Msg 3609, Level 16, State 2, Line 1 The transaction ended in the trigger. The batch has been aborted.
再執(zhí)行DROP的操作,同樣觸發(fā)警告
DROP TABLE MYTABLE(1 row(s) affected)You are not allowed to CREATE,ALTER and DROP any Tables and ProceduresMsg 3609, Level 16, State 2, Line 1The transaction ended in the trigger. The batch has been aborted. 因?yàn)槲覀兊挠|發(fā)器規(guī)定了不能使用CREATE_TABLE,DROP_TABLE, ALTER_TABLE,CREATE_PROCEDURE, ALTER_PROCEDURE,DROP_PROCEDURE等操作。;;如果我們要關(guān)掉這個(gè)觸發(fā)器,可以這樣做:; DISABLE TRIGGER STOP_DDL_ON_TABLE_AND_PROC ON DATABASE當(dāng)然,我們要對(duì)整個(gè)服務(wù)器采取策略的話(huà),也是很簡(jiǎn)單的,和上面的方法大致相同只不過(guò)將on database的參數(shù)改為on server,比如CREATE TRIGGER STOP_DDL_on_Table_and_PROCON ALL SERVERFOR CREATE_DATABASE,ALTER_DATABASE,DROP_DATABASEAS PRINT 'You are not allowed to CREATE,ALTER and DROP any Databases' ROLLBACK;
