????????????????????????????????IO????????????????????????д??????????????????????????????????????????IO???????????÷?????????????????? ????????oracle?????????Щ????????????????ó???????????????????Щ???

????1??Oracle?????л????????磬??????

????2????ú?????????

????3??????????oracle???????

????4?????????????????????IO??

????5????????????????????????????????????IO?????

????6?????????????????????洢???????????????任????????IO??

??????????????

????1????????????????????й????????????????????β?????10???????????????????????????

????2??Sql???????λ????????????????????漲??дsql??????????д?????Сд???oracle???????????????????У? ?磺

????select * from Emp where name=?????????????????????????????????????????????????????????????????????λ??Ч????

????3?????????????????洢??????????????????????????Щ??????????????????洢??????????????????????У??????????????????????????????

????4???????????*?????select * from Emp??????????????????????????????? ?????

????5???????Ч?????

??????????????????????oracle????????????????????????? oracle ?ж?????????FROM????????????????е??????????????????????? ???????????????????????????????link????????м??????????link??????????????????????????oracle??????????????????????????????????￡?????????????????????????????????????дsql

????6??Where??????

????Oracle ??Where??????????????????????????д????????????????????????????????????????where???β?? ????=????????н?????????????о????????????д??????????????????????????????? is null??is not null??????????????????

????7?????Exits Not Exits ??? In Not in

????8??????????????????????????????????????????????????????????????????????????????????????????????