Video: Dab tsi yog kev sib raug zoo database hauv Access?
2024 Tus sau: Lynn Donovan | [email protected]. Kawg hloov kho: 2023-12-15 23:47
A kev sib raug zoo hauv Nkag mus pab koj muab cov ntaub ntawv los ntawm ob lub rooj sib txawv. Txhua kev sib raug zoo muaj cov teb hauv ob lub rooj nrog cov ntaub ntawv sib xws. Thaum koj siv cov rooj sib tham hauv cov lus nug, tus kev sib raug zoo cia Nkag mus txiav txim siab seb cov ntaub ntawv twg los ntawm txhua lub rooj sib xyaw ua ke hauv cov txiaj ntsig tau teeb tsa.
Tsis tas li ntawd, kev sib raug zoo database yog dab tsi?
A kev sib raug zoo , nyob rau hauv cov ntsiab lus ntawm databases , yog qhov xwm txheej uas muaj nyob nruab nrab ntawm ob qho kev sib raug zoo database cov rooj thaum ib lub rooj muaj tus yuam sij txawv teb chaws uas hais txog qhov tseem ceeb ntawm lwm lub rooj. Kev sib raug zoo tso cai rau kev sib raug zoo databases cais thiab khaws cov ntaub ntawv hauv cov rooj sib txawv, thaum txuas cov khoom sib txawv.
Ib sab saum toj no, koj ua li cas tsim kev sib raug zoo hauv kev nkag? Koj txhais a kev sib raug zoo los ntawm kev ntxiv cov ntxhuav uas koj xav kom muaj kev sib raug zoo nrog lub qhov rais Kev Sib Raug Zoo, thiab tom qab ntawd rub lub chaw tseem ceeb ntawm ib lub rooj thiab muab tso rau ntawm qhov chaw tseem ceeb hauv lwm lub rooj.
Kev sib raug zoo, muaj pes tsawg hom kev sib raug zoo muaj nyob rau hauv kev nkag?
peb hom
Vim li cas kev sib raug zoo tseem ceeb hauv cov ntaub ntawv?
Ib qho laj thawj kev sib raug zoo muaj nyob nruab nrab ntawm cov ntaub ntawv hauv STUDENTS table thiab cov ntaub ntawv hauv STUDENT INSTRUMENTS table. Nws pab txhawm rau txhim kho cov txheej txheem rooj ntxiv thiab txo qis cov ntaub ntawv rov ua dua. Raws li koj tsim ib kev sib raug zoo nruab nrab ntawm ib khub ntawm lub rooj, koj yuav inevitably ua me kev hloov kho rau lub rooj qauv.
Pom zoo:
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 kev sib tshuam hauv kev sib raug zoo algebra?
INTERSECTION kev khiav hauj lwm nyob rau hauv RELATIONAL ALGEBRA. Kev sib tshuam ntawm teeb A thiab B = A ∩ B = {1, 6} Cov ntsiab lus uas muaj nyob rau hauv ob qho tib si A thiab B yuav tsuas muaj nyob rau hauv lub teeb tau los ntawm kev sib tshuam ntawm A thiab B
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