Video: Puas muaj kev sib raug zoo siv?
2024 Tus sau: Lynn Donovan | [email protected]. Kawg hloov kho: 2023-12-15 23:47
Hauv Java, a Muaj -A kev sib raug zoo tsuas yog txhais tau tias ib qho piv txwv ntawm ib chav kawm muaj ib qho kev siv rau ib qho piv txwv ntawm lwm chav kawm lossis lwm qhov piv txwv ntawm tib chav kawm. Piv txwv li, ib lub tsheb muaj ib engine, aub muaj ib tail. Hauv Java, tsis muaj lo lus tseem ceeb uas siv a Muaj -A kev sib raug zoo.
Ib yam li ib tug yuav nug, puas yog Versus muaj kev sib raug zoo?
Txhua qhov chaw koj pom ib lo lus txuas ntxiv los yog siv lo lus tseem ceeb hauv kev tshaj tawm hauv chav kawm, tom qab ntawd chav kawm no yog hais tias muaj YOG -A kev sib raug zoo . HAS-A kev sib raug zoo : Composition( YOG -A) tsuas yog txhais tau tias siv cov piv txwv hloov pauv uas yog hais txog lwm yam khoom. Piv txwv li Maruti muaj Cav, los yog Tsev muaj Chav dej.
Tsis tas li ntawd, puas yog ib feem ntawm kev sib raug zoo? “IS-A” kev sib raug zoo yog tag nrho raws li Inheritance, uas tuaj yeem yog ob hom Class Inheritance lossis Interface Inheritance. Piv txwv li yog "Apple yog txiv hmab txiv ntoo", "Ferrari yog lub tsheb". Composition yog " ib feem ntawm "kev sib raug zoo . Tsuas yog kev sib xyaw txhais tau tias yog siv cov piv txwv sib txawv uas yog siv rau lwm yam khoom.
Kuj paub, yog A thiab muaj kev sib raug zoo hauv DBMS?
Hauv kev tsim database, object-oriented programming thiab tsim (saib object oriented program architecture), muaj -a (has_a or muaj a) yog kev sib sau kev sib raug zoo qhov twg ib yam khoom (feem ntau hu ua cov khoom tsim, los yog ib feem / constituent / cov tswv cuab cov khoom) "yog" (yog ib feem lossis cov tswv cuab ntawm) lwm yam khoom (hu ua cov khoom sib xyaw
Puas yog kev sib raug zoo piv txwv?
Hauv Object oriented programming, IS-A kev sib raug zoo txhais tias "ib yam khoom yog hom ntawm lwm tus". YOG-A relation txhais tau tias Inheritance methodology. Nyob rau hauv Java, Inheritance tuaj yeem siv tau nrog txuas ntxiv (hauv chav kawm) thiab siv (thaum interface) cov ntsiab lus. Ib qho yooj yim piv txwv ntawm YOG-A relation : Dell IS-A laptop.
Pom zoo:
Kev sib cav sib ceg sib txawv li cas ntawm kev sib cav tsis zoo?
Txhua qhov kev sib cav tsis zoo siv txoj cai invalid inference. Yog tias qhov kev sib cav tsis zoo koj paub tias nws tsis siv. Kev siv tau txhais tau tias tsis muaj kev txhais lus qhov twg qhov chaw muaj tseeb thiab qhov kev txiav txim siab tuaj yeem tsis tseeb ib txhij. Yog tias qhov kev sib cav ua txhaum koj tuaj yeem tsis quav ntsej nws thiab sim nkag siab lub ntsiab lus tseem
Vim li cas kev sib raug zoo algebra siv nyob rau hauv kev sib raug zoo database tswj?
RELATIONAL ALGEBRA yog ib hom lus nug uas siv dav heev. Nws sau cov xwm txheej ntawm kev sib raug zoo raws li kev tawm tswv yim thiab muab qhov tshwm sim ntawm kev sib raug zoo raws li cov zis. Nws siv ntau yam haujlwm los ua qhov haujlwm no. Relational algebra operations yog ua recursively ntawm kev sib raug zoo
Dab tsi yog qhov txawv ntawm kev sib raug zoo unary kev sib raug zoo binary thiab kev sib raug zoo ternary?
Kev sib raug zoo tsis sib xws yog thaum ob tus neeg koom hauv kev sib raug zoo yog tib lub koom haum. Piv txwv li: Cov ncauj lus yuav yog qhov yuav tsum tau ua ua ntej rau lwm yam kev kawm. Kev sib raug zoo ternary yog thaum peb lub koom haum koom nrog kev sib raug zoo
Dab tsi yog qhov txawv ntawm kev sib raug zoo thiab tsis muaj kev sib raug zoo databases?
Qhov sib txawv loj ntawm lawv yog li cas lawv tuav cov ntaub ntawv. Relational databases are structured.Non-relational databases are document-oriented. Qhov no hu ua cov ntaub ntawv hom cia tso cai ntau 'qeb' ntawm cov ntaub ntawv khaws cia hauv ib qho kev tsim lossis Cov Ntaub Ntawv
Dab tsi yog qee qhov tsis zoo ntawm lub sijhawm stamping txoj hauv kev rau kev tswj hwm kev sib raug zoo?
Qhov tsis zoo ntawm lub sij hawm stamping mus kom ze yog tias txhua tus nqi khaws cia hauv cov ntaub ntawv yuav tsum muaj ob lub sij hawm thwj ntxiv: ib qho rau lub sijhawm kawg ntawm daim teb tau nyeem thiab ib qho rau qhov hloov tshiab kawg. Lub sij hawm stamping yog li ua rau kom nco xav tau thiab cov ntaub ntawv ua haujlwm nyiaj siv ua haujlwm