Koj txhais li cas los ntawm kev tswj cov ntaub ntawv?
Koj txhais li cas los ntawm kev tswj cov ntaub ntawv?

Video: Koj txhais li cas los ntawm kev tswj cov ntaub ntawv?

Video: Koj txhais li cas los ntawm kev tswj cov ntaub ntawv?
Video: Ib tug neeg yuav tsum raug 3 nqi no. Ntsib lawm yuav ua li cas ? 02/10/2021 2024, Kaum ib hlis
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Cov ntaub ntawv tswj yog tus txheej txheem tswj thiab tswj cov ntaub ntawv . Nws yog ib hom kev sab hauv tswj tsim los ua kom tiav cov ntaub ntawv kev tswj hwm thiab cov ntaub ntawv lub hom phiaj tswj. Cov hauv qab no yog cov piv txwv ntawm tswj cov ntaub ntawv.

Ib yam li ntawd, peb txhais li cas los ntawm cov ntaub ntawv?

Cov ntaub ntawv yog cov ntaub ntawv sib txawv, feem ntau formatted hauv ib txoj kev tshwj xeeb. Txij li thaum nruab nrab-1900s, tib neeg tau siv lo lus cov ntaub ntawv rau txhais tau tias cov ntaub ntawv hauv computer uas kis tau lossis khaws cia. Hais lus nruj, cov ntaub ntawv yog lub plural ntawm datum, ib daim ntaub ntawv.

Ib yam li ntawd, cov ntaub ntawv thiab piv txwv ntawm cov ntaub ntawv yog dab tsi? Cov ntaub ntawv txhais tau tias yog qhov tseeb lossis cov duab, lossis cov ntaub ntawv uas khaws cia hauv lossis siv los ntawm lub computer. Ib piv txwv ntawm cov ntaub ntawv yog cov ntaub ntawv sau rau ib daim ntawv tshawb fawb. Ib piv txwv ntawm cov ntaub ntawv yog email.

Raws li, kev tswj cov ntaub ntawv hauv DBMS yog dab tsi?

A tswj cov ntaub ntawv lus (DCL) yog syntax zoo ib yam li computer programming lus siv los tswj nkag mus rau cov ntaub ntawv khaws cia rau hauv ib lub database (Authorization). Tshwj xeeb, nws yog ib feem ntawm Structured Query Language (SQL). Piv txwv ntawm DCL cov lus txib suav nrog: GRANT tso cai rau cov neeg siv tshwj xeeb los ua cov haujlwm tshwj xeeb.

Koj txhais li cas los ntawm cov ntaub ntawv hauv kev txheeb cais?

cov ntaub ntawv yog ib qho ntawm cov ntaub ntawv tseeb raug kaw thiab siv rau lub hom phiaj ntawm kev tshuaj xyuas. Nws yog cov ntaub ntawv nyoos los ntawm qhov twg txheeb cais yog tsim. Statistics yog cov txiaj ntsig ntawm cov ntaub ntawv tsom xam - nws txhais lus thiab kev nthuav qhia. Feem ntau cov hom no txheeb cais yog hu ua ' cov ntaub ntawv txheeb cais '.

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