Oracle??SQL???????????
???????????? ???????[ 2014/7/14 10:29:08 ] ????????Oracle SQL??? ?????
??????????????Oracle?????SQL??????????????????????????????????????????????????????????????кβ????????????????????ν??н??????Oracle??????????????????ν??е??????????????Щ??????й??????
??????Oracle?д????????????SQL???????DDL???????????????????????????????ж????????????????????????DML?????????????????????????????????????????????Oracle 8i OCP????023??1-12?????SQL??????????裬?????SQL????????????????????????????????????2??裺
???? ???????????? SQL ???????и???
???? ??? SQL ???????????
???? ??????????????????????е????
???? ??????????????????????????????ж??????岻????
???? ?????????????÷???????????
???? ??????????м??
???? ????????м????????? SQL ??
?????????????????????????????????????????????????漸?????衣???????????????????????????????????????SQL??????????????????????????????????????????????ü??????裬?????????????????????С??????????????????????????????????????????????????Tom???Effective Oracle By Design???й?????????????????????????????????????????????
????????????Oracle??SQL??????????????£?
????1????????ж????SQL????????????SQL??淶????????У?SQL> selet * from emp;??????????????Select????????????“c”????????????????????????????
????2???????顣???????SQL?????????????????????ж??SQL???????????????????????????????????????????????У????????????
????SQL> select * from emp;
????select * from emp
????*
????ERROR at line 1:
????ORA-00942: table or view does not exist
???????????????п???????emp????????SQL??????????????顣
????3????鹲????????????????????????????е?SQL?????????????д??????????????????SQL??佫??????????????????????????????????м???????????????????????????????к?????????裬????????????????????????????????????????????????????裺
??????1???????SQL???????????????????????У?Oracle?????????????SQL??????HASH????????ó?HASH????????????????????HASH????б????????????????????????SQL????HASH???????????????v$sql??v$sqlarea??v$sqltext??????????е?HASH_VALUE?в???ó??????SQL????HASH???£????ORACLE???????????SQL?????????????μ????????????????????Oracle?????ζ??????????м?????????SQL????HASH?????????????????????SQL????HASH???????????????????????????SQL????????????????????????ο?????????????
???????????A???????????EMP???????в?????select * from emp?????B??????EMP??????????select * from emp???????????????????????????????????????HASH??????????????????漰?????????????????????????????????????????????????C????????????????????????scott?μ???????????????SCOTT????????????????emp???????????????
??????
???·???
??????????????????
2023/3/23 14:23:39???д?ò??????????
2023/3/22 16:17:39????????????????????Щ??
2022/6/14 16:14:27??????????????????????????
2021/10/18 15:37:44???????????????
2021/9/17 15:19:29???·???????·
2021/9/14 15:42:25?????????????
2021/5/28 17:25:47??????APP??????????
2021/5/8 17:01:11