Cov txheej txheem:
Video: Vim li cas peb thiaj siv cov ntaub ntawv sib raug zoo?
2024 Tus sau: Lynn Donovan | [email protected]. Kawg hloov kho: 2023-12-15 23:47
A kev sib txheeb database tso cai rau koj kom yooj yim nrhiav cov ntaub ntawv tshwj xeeb. Nws kuj tso cai rau koj txheeb raws li ib daim teb thiab tsim cov ntawv ceeb toom uas tsuas muaj qee qhov chaw los ntawm txhua cov ntaub ntawv. Relational databases siv cov rooj khaws ntaub ntawv.
Hais txog qhov no, vim li cas cov ntaub ntawv sib raug zoo yog nrov?
Cov Relational database ua nrov vim SQL thiab nws cov programming abstraction. SQL yog lub ntsiab interface rau querying kev sib txheeb databases . SQL programming qauv zoo ib yam li teeb tsa kev ua haujlwm uas yooj yim kawm. Cov Relational database ua nrov vim SQL thiab nws cov programming abstraction.
Tsis tas li ntawd, lub luag haujlwm ntawm kev sib raug zoo database hauv ib lub koom haum niaj hnub no yog dab tsi? DBMS tso cai rau muab faib, sau npe thiab nkag rau cov no database hom. Cov kev sib raug zoo qauv yog ib qho piv txwv ntawm cov ntaub ntawv raws li qauv. Kev ruaj ntseg cov ntaub ntawv yog ib qho tseem ceeb feature rau txhua yam ntaub ntawv system. DBMS muab cov rooj ruaj ntseg, uas yog cov ntaub ntawv tsim los rau cov neeg siv cov ntaub ntawv, kev txheeb xyuas thiab passwords.
Xav txog qhov no, koj siv cov ntaub ntawv sib txheeb li cas?
Relational Database Design Process
- Kauj Ruam 1: Txhais Lub Hom Phiaj ntawm Database (Yuav tsum tau tsom xam)
- Kauj Ruam 2: Sau cov ntaub ntawv, teeb tsa hauv cov ntxhuav thiab qhia cov yuam sij tseem ceeb.
- Kauj Ruam 3: Tsim Kev Sib Raug Zoo ntawm Cov Rooj.
- Kauj Ruam 4: Ua kom zoo & normalize tus tsim.
Excel puas yog cov ntaub ntawv sib raug zoo?
Excel cov lub koom haum qauv qiv nws tus kheej zoo li cas databases ua haujlwm. Ib daim ntawv qhia, ib leeg, yog a database , tab sis tsis yog a kev sib raug zoo ib. Cov kev sib txheeb database yog ib qho kev sib txuas ntawm Master spreadsheet tables thiab tag nrho nws cov Slave tables los yog spreadsheets.
Pom zoo:
Vim li cas cov ntaub ntawv tiaj tus tsis zoo dua li cov ntaub ntawv sib raug zoo?
Ib lub rooj ua ntaub ntawv tiaj tus yog qhov tseem ceeb rau kev sau cov ntaub ntawv tsawg. Tab sis cov ntaub ntawv loj loj tuaj yeem ua tsis tau raws li nws siv ntau qhov chaw thiab nco dua li cov ntaub ntawv sib txheeb. Nws kuj yuav tsum tau muab cov ntaub ntawv tshiab ntxiv txhua zaus koj nkag mus rau cov ntaub ntawv tshiab, qhov kev sib raug zoo database tsis
Vim li cas cov tuam txhab siv cov ntaub ntawv sib raug zoo?
Qhov txiaj ntsig tseem ceeb ntawm kev sib raug zoo databaseapproach yog lub peev xwm los tsim cov ntaub ntawv tseem ceeb los ntawm kev koom nrog cov rooj. Kev koom nrog cov rooj tso cai rau koj nkag siab txog kev sib txuas ntawm cov ntaub ntawv, lossis cov rooj sib txuas li cas. SQL suav nrog kev muaj peev xwm suav, ntxiv, pab pawg, thiab sib txuas lus
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
Vim li cas kem taw qhia cov ntaub ntawv khaws cia ua cov ntaub ntawv nkag ntawm disks sai dua li kab qhia cov ntaub ntawv khaws cia?
Kem oriented databases (aka columnar databases) yog qhov tsim nyog rau kev ntsuas kev ua haujlwm ntau dua vim tias cov ntaub ntawv hom ntawv (kem hom) qiv nws tus kheej kom nrawm dua cov lus nug ua - scans, aggregation thiab lwm yam. Ntawm qhov tod tes, kab oriented databases khaws ib kab (thiab tag nrho nws. kab) contiguously