PLSQL-Users-Guide-and-Reference

Oracle®DatabasePL/SQLUser'sGuideandReference10gRelease2(10.2)B14261-01June2005OracleDatabasePL/SQLUser’sGuideandReference10gRelease2(10.2)B14261-01Copyright©1996,2005,Oracle.Allrightsreserved.Contributors:ShashaankaAgrawal,CaileinBarclay,EricBelden,DmitriBronnikov,SharonCastledine,ThomasChang,RavindraDani,ChandrasekharanIyer,SusanKotsovolos,NeilLe,WarrenLi,BrynLlewellyn,ValarieMoore,ChrisRacicot,MuraliVemulapati,JohnRussell,GuhanViswanathan,MinghuiYangThePrograms(whichincludeboththesoftwareanddocumentation)containproprietaryinformation;theyareprovidedunderalicenseagreementcontainingrestrictionsonuseanddisclosureandarealsoprotectedbycopyright,patent,andotherintellectualandindustrialpropertylaws.Reverseengineering,disassembly,ordecompilationofthePrograms,excepttotheextentrequiredtoobtaininteroperabilitywithotherindependentlycreatedsoftwareorasspecifiedbylaw,isprohibited.Theinformationcontainedinthisdocumentissubjecttochangewithoutnotice.Ifyoufindanyproblemsinthedocumentation,pleasereportthemtousinwriting.Thisdocumentisnotwarrantedtobeerror-free.ExceptasmaybeexpresslypermittedinyourlicenseagreementforthesePrograms,nopartoftheseProgramsmaybereproducedortransmittedinanyformorbyanymeans,electronicormechanical,foranypurpose.IftheProgramsaredeliveredtotheUnitedStatesGovernmentoranyonelicensingorusingtheProgramsonbehalfoftheUnitedStatesGovernment,thefollowingnoticeisapplicable:U.S.GOVERNMENTRIGHTSPrograms,software,databases,andrelateddocumentationandtechnicaldatadeliveredtoU.S.GovernmentcustomersarecommercialcomputersoftwareorcommercialtechnicaldatapursuanttotheapplicableFederalAcquisitionRegulationandagency-specificsupplementalregulations.Assuch,use,duplication,disclosure,modification,andadaptationofthePrograms,includingdocumentationandtechnicaldata,shallbesubjecttothelicensingrestrictionssetforthintheapplicableOraclelicenseagreement,and,totheextentapplicable,theadditionalrightssetforthinFAR52.227-19,CommercialComputerSoftware—RestrictedRights(June1987).OracleCorporation,500OracleParkway,RedwoodCity,CA94065TheProgramsarenotintendedforuseinanynuclear,aviation,masstransit,medical,orotherinherentlydangerousapplications.Itshallbethelicensee'sresponsibilitytotakeallappropriatefail-safe,backup,redundancyandothermeasurestoensurethesafeuseofsuchapplicationsiftheProgramsareusedforsuchpurposes,andwedisclaimliabilityforanydamagescausedbysuchuseofthePrograms.Oracle,JDEdwards,PeopleSoft,andRetekareregisteredtrademarksofOracleCorporationand/oritsaffiliates.Othernamesmaybetrademarksoftheirrespectiveowners.TheProgramsmayprovidelinkstoWebsitesandaccesstocontent,products,andservicesfromthirdparties.Oracleisnotresponsiblefortheavailabilityof,oranycontentprovidedon,third-partyWebsites.Youbearallrisksassociatedwiththeuseofsuchcontent.Ifyouchoosetopurchaseanyproductsorservicesfromathirdparty,therelationshipisdirectlybetweenyouandthethirdparty.Oracleisnotresponsiblefor:(a)thequalityofthird-partyproductsorservices;or(b)fulfillinganyofthetermsoftheagreementwiththethirdparty,includingdeliveryofproductsorservicesandwarrantyobligationsrelatedtopurchasedproductsorservices.Oracleisnotresponsibleforanylossordamageofanysortthatyoumayincurfromdealingwithanythirdparty.iiiContentsSendUsYourComments.....................................................................................................................xviiPreface...............................................................................................................................................................xixAudience.....................................................................................................................................................xixDocumentationAccessibility...................................................................................................................xixStructure.....................................................................................................................................................xxPL/SQLSamplePrograms.......................................................................................................................xxiRelatedDocuments..................................................................................................................................xxiiConventions..............................................................................................................................................xxiiWhat'sNewinPL/SQL?.........................................................................................................................xxvNewFeaturesinPL/SQLforOracleDatabase10gRelease2(10.2)................................................xxvNewFeaturesinPL/SQLforOracleDatabase10gRelease1(10.1)................................................xxvi1OverviewofPL/SQLAdvantagesofPL/SQL............................................................................................................................1-1TightIntegrationwithSQL...............................................