Cov txheej txheem:
Video: Dab tsi yog data modeling nrog piv txwv?
2024 Tus sau: Lynn Donovan | [email protected]. Kawg hloov kho: 2023-12-15 23:47
Cov ntaub ntawv cov qauv yog tsim los ntawm cov chaw, uas yog cov khoom lossis cov ntsiab lus peb xav taug qab cov ntaub ntawv txog, thiab lawv dhau los ua cov ntxhuav hauv cov ntaub ntawv. Cov khoom, cov neeg muag khoom, thiab cov neeg siv khoom yog txhua yam piv txwv ntawm cov chaw muaj peev xwm hauv a cov ntaub ntawv qauv . Kev sib raug zoo ntawm cov koom haum tuaj yeem yog ib-rau-ib, ib-rau-ntau, lossis ntau-rau-ntau.
Tsuas yog li ntawd, Data Modeling yog dab tsi?
Cov ntaub ntawv qauv yog ib txoj kev siv rau txhais thiab txheeb xyuas cov ntaub ntawv cov kev xav tau xav tau los txhawb cov txheej txheem kev lag luam nyob rau hauv cov peev txheej ntawm cov ntaub ntawv sib txuas hauv cov koom haum.
Tsis tas li ntawd, cov qauv ntawm cov ntaub ntawv yog dab tsi? Muaj peb lub ntsiab qauv ntawm cov ntaub ntawv qauv zoo li lub tswv yim, kev xav, thiab lub cev. Ib lub tswv yim qauv yog siv los tsim cov koom haum, cwj pwm, thiab kev sib raug zoo. Ib qho laj thawj cov ntaub ntawv qauv yog los txhais cov qauv ntawm cov cov ntaub ntawv cov ntsiab lus thiab teeb tsa kev sib raug zoo ntawm lawv.
Ib yam li ntawd, tsib kauj ruam ntawm kev tsim cov ntaub ntawv yog dab tsi?
Peb tau tawg nws ua tsib kauj ruam:
- Kauj ruam 1: Nkag siab koj daim ntawv thov kev ua haujlwm.
- Kauj ruam 2: Ua qauv cov lus nug uas yuav tsum tau los ntawm daim ntawv thov.
- Kauj Ruam 3: Tsim cov rooj.
- Kauj Ruam 4: Txiav txim siab thawj tus yuam sij.
- Kauj Ruam 5: Siv hom ntaub ntawv kom zoo.
Tus qauv txheej txheem cov ntaub ntawv yog dab tsi?
Cov txheej txheem qauv yog ib daim duab tseem ceeb hauv kev tsom xam thiab tsim qauv. Kuj hu ua a cov ntaub ntawv Flow Diagram (DFD), nws qhia txog kev khiav ntawm cov ntaub ntawv los ntawm qhov system. Txhua txheej txheem transforms inputs rau hauv outputs. Flow kab sawv cev cov ntaub ntawv ntws ntawm nodes suav nrog txheej txheem , lwm cov koom haum thiab cov ntaub ntawv khw.
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