oracle:SAVEPOINT(保存点)
?以下內(nèi)容轉(zhuǎn)載自:
?https://mp.weixin.qq.com/s?__biz=MzIzOTA2NjEzNQ==&mid=2454771894&idx=2&sn=f605c49f7ad63c6051e680cee44d3733&chksm=fe8bb5cec9fc3cd8ddac9f1c022b471d5489e602c76012299e3150d4d822ec313b1fb90c3e2e&scene=21#wechat_redirect
create table EMPLOYEE (first_name VARCHAR2(20),last_name ?VARCHAR2(25),salary ? ? NUMBER(8,2) );-- 創(chuàng)建存儲(chǔ)過(guò)程 create or replace procedure SavepointTest isBEGININSERT INTO EMPLOYEE(SALARY,LAST_NAME,FIRST_NAME) VALUES(35000,'WANG','FRED');SAVEPOINT SAVE_A;INSERT INTO EMPLOYEE(SALARY,LAST_NAME,FIRST_NAME) VALUES(40000,'WOO','DAVID');SAVEPOINT SAVE_B;INSERT INTO EMPLOYEE(SALARY,LAST_NAME,FIRST_NAME) VALUES(50000,'LDD','FRIK');SAVEPOINT SAVE_C;INSERT INTO EMPLOYEE(SALARY,LAST_NAME,FIRST_NAME) VALUES(45000,'LHR','DAVID');INSERT INTO EMPLOYEE(SALARY,LAST_NAME,FIRST_NAME) VALUES(25000,'LEE','BERT');ROLLBACK TO SAVEPOINT SAVE_C;INSERT INTO EMPLOYEE(SALARY,LAST_NAME,FIRST_NAME) VALUES(32000,'CHUNG','MIKE');ROLLBACK TO SAVEPOINT SAVE_B;COMMIT;END;?執(zhí)行存儲(chǔ)過(guò)程
?查詢表,結(jié)果只插入了兩條數(shù)據(jù),這就是存錯(cuò)過(guò)程中的savepoint的作用.
?
?
保存點(diǎn)(SAVEPOINT)是事務(wù)處理過(guò)程中的一個(gè)標(biāo)志,與回滾命令(ROLLBACK)結(jié)合使用。其主要用途是允許用戶將某一段處理進(jìn)行回滾而不必回滾整個(gè)事務(wù)。
1)執(zhí)行SAVEPOINT SAVE_A的時(shí)候創(chuàng)建了一個(gè)保存點(diǎn)SAVE_A;
2)執(zhí)行SAVEPOINT SAVE_B的時(shí)候創(chuàng)建了一個(gè)保存點(diǎn)SAVE_B;
3)執(zhí)行SAVEPOINT SAVE_C的時(shí)候創(chuàng)建了一個(gè)保存點(diǎn)SAVE_C;
4)在執(zhí)行ROLLBACK TO SAVEPOINT SAVE_C后,SAVEPOINT SAVE_C到當(dāng)前語(yǔ)句之間所有的操作都被回滾;也就是說(shuō)回滾到了3)的狀態(tài);
5)在執(zhí)行ROLLBACK TO SAVEPOINT SAVE_B后,SAVEPOINT SAVE_B到當(dāng)前語(yǔ)句之間所有的操作都被回滾;也就是說(shuō)回滾到了2)的狀態(tài);
6)在執(zhí)行COMMIT后,只有SAVEPOINT SAVE_B之前的操作會(huì)被提交從而永久保存到數(shù)據(jù)庫(kù)。
總結(jié)
以上是生活随笔為你收集整理的oracle:SAVEPOINT(保存点)的全部?jī)?nèi)容,希望文章能夠幫你解決所遇到的問(wèn)題。
- 上一篇: oracle:自定义函数
- 下一篇: oracle:小知识点