2094-BC02-M02-S,2094-BC02-M02-S
2094-BC02-M02-S2094-BC02-M02-S觸發(fā)器有如下作用:
-
可在寫(xiě)入數(shù)據(jù)表前,強(qiáng)制檢驗(yàn)或轉(zhuǎn)換數(shù)據(jù)。
-
觸發(fā)器發(fā)生錯(cuò)誤時(shí),異動(dòng)的結(jié)果會(huì)被撤銷(xiāo)。
-
部份數(shù)據(jù)庫(kù)管理系統(tǒng)可以針對(duì)數(shù)據(jù)定義語(yǔ)言(DDL)使用觸發(fā)器,稱(chēng)為DDL觸發(fā)器。
-
可依照特定的情況,替換異動(dòng)的指令 (INSTEAD OF)。當(dāng)數(shù)據(jù)庫(kù)中表中的數(shù)據(jù)發(fā)生變化時(shí),包括insert,update,delete任意操作,如果我們對(duì)該表寫(xiě)了對(duì)應(yīng)的DML觸發(fā)器,那么該觸發(fā)器自動(dòng)執(zhí)行。DML觸發(fā)器的主要作用在于強(qiáng)制執(zhí)行業(yè) 務(wù)規(guī)則,以及擴(kuò)展Sql Server約束,默認(rèn)值等。因?yàn)槲覀冎兰s束只能約束同一個(gè)表中的數(shù)據(jù),而觸發(fā)器中則可以執(zhí)行任意Sql命令。
mac093a-0-ps-4-c/110-a-0/wi538lx/s001 indramat servo motors remanufactured
mac093b-0-js-2-c/130-b-0/s005 indramat servo motors remanufactured
mac112a-0-ld-1-b/130-a-0/j1250/s05 indramat servo motors remanufactured
mac112a-0-ld-3-c/130-a-0/s005 indramat servo motors remanufactured
mac112a-0-ld-4-c/130-a-0/wi520l/s05 indramat servo motors remanufactured
mac112a-0-vd-3-c/130-a-0 indramat servo motors remanufactured
mac112a-0-vd-4-c/130-a-1/wi524lv/s005 indramat servo motors remanufactured
mac112b-0-gd/130-1/i-625/s05 indramat servo motors remanufactured
mac112b-0-gd-1-b/130-a-0/i1250/s005 indramat servo motors remanufactured
mac112b-0-gd-1-b/130-a-0/j625/s05 indramat servo motors remanufactured
mac112b-0-gd-1-b/130-a-o/j1250/s05 indramat servo motors remanufactured
mac112b-0-gd-1-l/130-a-0/j625/s05 indramat servo motors remanufactured
上一篇:
1756-L71
下一篇:
2094-BM02-S