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ABAP/4Dictionary

ObjectivesChapter2

IntegrationintoABAP/4Workbench（Active）

⏹TheABAP/4Dictionaryisanactive,integralcomponentoftheABAP/4DevelopmentWorkbench.AnychangemadeintheDictionarybecomeseffectiveatonceintherelevantABAP/4programsandscreens.

⏹ThebasisforthisistheinterpretivenatureoftheR/3Systems.TheinterpreterdoesnotoperatedirectlyontheoriginalcodeofanABAP/4programorscreen,butinterpretsagenerated,internalrepresentation.

⏹WhenchangesaremadeintheABAP/4Dictionary,automaticpost-generationofthisinternalrepresentationguaranteesthattheinterpreterisalwaysworkingwiththelatestdata.

BasicDictionaryObjects

⏹ThebasicdatadefinitionobjectsintheABAP/4Dictionaryaretables,domainsanddataelements.Domainsdescribethetechnicalattributesoftablefields（e.g.fieldtype,fieldlength）,whiledataelementscontainthesemanticdefinition（e.g.shortdescription）.

⏹Fieldsarenotindependentobjectsandcanonlybemaintainedwithintables.Theypresupposetheexistenceofadataelement.

⏹Adataelementpresupposestheexistenceofadomain.

⏹DomainscanbedefinedwithoutfurtherreferencetootherDictionaryobjects.

DualLevelDomainConcept

⏹IntheABAP/4Dictionary,twotypesofobjectsareusedfordatadefinitionpurposes.Thesearetechnicaldomains（knownasdomainsintheR/3System）andsemanticdomains（knownasdataelementsintheR/3System）.

⏹Thedomainisthecentralobjectusedtodescribetheattributesofabusinessobject.Itdescribesafield’svaluerangewhichisdefinedbyspecifyingformalattributessuchasexternalformatandlengthandbyspecifyingfixedvaluesoravaluetable.

⏹Thedataelementisthesemanticobject.Itdescribespreciselythepurposeofadomaininaparticularbusinesssettingforthefieldswhichdependonit.

⏹Forexample,thetablefieldsFORCURAM（tableSBOOK）andPRICE（tableSFLIGHT）belongtothesamedomainS_PRICE.Todistinguishtheiractualbusinessapplication,thefieldFORCURAMusesthedataelementS_F_CUR_PRandthefieldPRICEusesthedataelementS_PRICE.However,bothfieldsbelongtothesamedomainbecausetheyarecurrencyfieldsandthushavesimilartechnicalatttributes.

TransparentTables

⏹WhenithasbeenactivatedintheABAP/4Dictionary,atransparenttableisautomaticallycreatedinthedatabase.Thisprocesstranslatesthedatabase-independentdescriptionofthetableintheABAP/4Dictionaryintothelanguageofthedatabasesystembeingused.

⏹ThedatabasetablehasthesamenameasthetableintheABAP/4Dictionary.ThefieldsalsohavethesamenamesinboththedatabaseandintheABAP/4Dictionary.ThedatatypesintheABAP/4Dictionaryareconvertedtothecorrespondingdatatypesofthedatabasesystem.

⏹AsofRelease3.0,thesequenceoffieldsintheABAP/4Dictionarycanvaryfromthesequenceoffieldsinthedatabase.Thisallowsyoutoinsertnewfieldswithouthavingtoconvertthetablebyperformingaphysicalreorganization.Whenaddingnewfields,theadjustmentismadebychangingthedatabasecatalog（ALTERTABLE）.Anewfieldisappendedtothedatabasetable,regardlessofitspositionintheABAP/4Dictionary.

CreatingTransparentTables

⏹ByactivatingatableoftypeTRANSPintheABAP/4Dictionary,youautomaticallycreatethetableviathedatabaseutilityinthedatabase.

⏹Onlycomplexdatabaseoperationssuchastableconversionsmustbeperformeddirectlyviathedatabaseutility.Simpleoperations,suchascreatingobjects,canbeperformedautomaticallybyactivatingtheobjectsintheABAP/4Dictionary.

⏹Inthedatabaseutility,youcancontrolthedatabaseobjectswithananalysistool.

Structures

⏹Besidesdefiningtablesstoredinthedatabase,youcanalsodefinethestructureofdatawhichoccurswhenperformingcalculationsinprograms,orwhenpassingdatabetweenprograms,globallyintheABAP/4Dictionary.Thiskindofdefinitionisknownasastructure.

⏹Structuresdonotcorrespondtoobjectsinthedatabase.

⏹StructuresaredefinedandactivatedintheABAP/4Dictionary.TheycanthenbeaddressedbyABAP/4programsliketablesdeclaredintheTABLESstatement.

⏹Whiledatacanbepermanentlystoredintransparenttablesinthedatabase,datainstructuresexistsonlyduringtheruntimeofaprogram.

⏹Structuresareusedinparticularfordefiningdataattheinterfaceofmodulepoolsandscreens,aswellasforassigningthetypestotheparametersofreusablefunctionmodulesorsubroutines.

⏹Definingstructurescentrallymeansthatyoucanchangethemcentrally.TheactiveABAP/4Dictionarythenensuresthatanymodificationsaremadeinalltheplacesconcerned.

CreatingStructures

⏹Todefineastructure,yougointotheObjectBrowserandproceedasfollows:

-UnderSingleobjects,selectDictionaryobjects.

-OntheDictionaryobjectsscreen,selectStructure.

⏹Onthenextscreen,youcanenterthefieldnamesofyourstructureandspecifythenameofanexistingdataelement（ordefineanewone）whichpointstoadomain.

⏹Whencheckedandfoundtohavenoerrors,thestructureissavedandactivatedandisreadyforuse.

AggregatedObjectsintheABAP/4Dictionary:

Views

⏹‘Aggregated’meansconsistingofseveralcomponents.IntheABAP/4Dictionary,aggregatedobjectsareobjectswhichcomefromseveraldifferenttransparenttables.

⏹Viewsareapplication-specificviewsofdifferentABAP/4Dictionarytables.

⏹ViewsallowyoutogatherinformationfromthefieldsofdifferenttablesandpresentittousersintheformtheyrequirewhenworkingwiththeR/3System.

⏹ViewsaremainlyusedforprogrammingwithABAP/4andforF4onlinehelp.

Summary（Chapter2）

Exercises（Chapter02）

ExercisesChapter2:

ABAP/4Dictionary

%Nameofyourstructure:

ZCA##

##:

Groupnumber

Task:

DefineanABAP/4Dictionarystructure（youwillusethisinalaterexercise）.

Thestructureshouldconsistofthefollowingfields:

FieldnameDataelement

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CARRIDS_CARR_ID

SEATSMAXS_SEATSMAX