Video: Kev sib raug zoo tag nrho yog dab tsi?
2024 Tus sau: Lynn Donovan | [email protected]. Kawg hloov kho: 2023-12-15 23:47
Tag nrho / Kev Sib Raug Zoo . Tag nrho / kev sib raug zoo yog thaum ib hoob sawv cev rau tag nrho khoom thiab lwm yam chav kawm sawv cev ntu . Cov tag nrho ua raws li lub thawv rau lub ntu . Cov no kev sib raug zoo yog qhia nyob rau hauv chav kawm daim duab kos los ntawm ib kab nrog lub pob zeb diamond ntawm ib kawg.
Ib yam li ntawd, kev sib raug zoo yog dab tsi?
Kev sib xyaw yog ib daim ntawv txwv ntawm Aggregation uas ob lub koom haum muaj kev vam khom rau ib leeg. Nws sawv cev ib feem ntawm kev sib raug zoo . Hauv muaj pes tsawg leeg , ob lub koom haum yog nyob ntawm ib leeg. Thaum muaj ib tug muaj pes tsawg leeg nruab nrab ntawm ob qhov chaw, cov khoom tsim tsis tuaj yeem nyob tsis muaj lwm qhov chaw.
Dab tsi yog kev sib raug zoo hauv UML? Nyob rau hauv object-oriented programming no kev sib raug zoo tuaj yeem sawv cev nrog Unified Modeling Language Class diagram. Qhov no muaj kev sib raug zoo tseem hu ua muaj pes tsawg leeg. Thaum lub pob zeb diamond dawb qhia kev sib sau , uas txhais tau hais tias cov khoom ze tshaj plaws ntawm lub pob zeb diamond tuaj yeem muaj lossis muaj lwm yam khoom.
Tsis tas li ntawd, dab tsi yog tag nrho hierarchy?
Ib qho system muaj cov subsystems lossis cov khoom siv. Cheebtsam ntxiv tuaj yeem muab faib ua cov khoom me me. Ntxiv cov khoom me me tuaj yeem muab faib ua cov khoom me me. Qhov no yog ib ib feem - tag nrho hierarchy . Txhua yam nyob ib puag ncig peb tuaj yeem yog tus neeg sib tw rau ib feem - tag nrho hierarchy.
Puas yog ib daim ntawv tshwj xeeb ntawm kev koom tes uas qhia txog tag nrho ib feem kev sib raug zoo ntawm cov aggregate tag nrho thiab ib feem?
Composite kev sib sau (composition) yog "muaj zog" daim ntawv ntawm aggregation nrog cov yam ntxwv hauv qab no: nws yog binary kev koom tes , yog a tag nrho / kev sib raug zoo , a ib feem tuaj yeem suav nrog feem ntau ntawm ib qho kev sib xyaw ( tag nrho ) ntawm ib lub sijhawm, thiab.
Pom zoo:
Dab tsi yog tag nrho cov kab kev sib txuas lus uas xav tau rau kev sib txuas tag nrho rau taw tes network ntawm tsib lub khoos phis tawj rau lub khoos phis tawj?
Tus naj npawb ntawm cov kab sib txuas lus uas yuav tsum tau muaj rau kev sib txuas tag nrho ntawm qhov taw tes rau-taw tes ntawm yim lub khoos phis tawj yog nees nkaum yim. Ib tug tag nrho txuas cuaj lub computer network yuav tsum tau peb caug rau kab. Ib tug tag nrho txuas kaum lub computer network yuav tsum tau plaub caug tsib kab
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