Dab tsi yog qhov kev siv ntawm kev sib raug zoo algebra hauv DBMS?
Dab tsi yog qhov kev siv ntawm kev sib raug zoo algebra hauv DBMS?

Video: Dab tsi yog qhov kev siv ntawm kev sib raug zoo algebra hauv DBMS?

Video: Dab tsi yog qhov kev siv ntawm kev sib raug zoo algebra hauv DBMS?
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RELATIONAL ALGEBRA yog dav siv txheej txheem lus nug. 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 kev khiav hauj lwm yog ua recursively ntawm kev sib raug zoo.

Hais txog qhov no, qhov twg yog relational algebra siv?

Relational Algebra yog cov lus nug txheej txheem, uas yuav siv Kev Sib Raug Zoo li kev tawm tswv yim thiab tsim kom muaj kev sib raug zoo raws li cov zis. Relational algebra mas muab theoretical foundation rau kev sib raug zoo databases thiab SQL. Projection yog siv rau qhov project xav tau kab ntawv los ntawm kev sib raug zoo.

Tsis tas li ntawd, dab tsi yog qhov haujlwm tseem ceeb ntawm kev sib raug zoo algebra? Tsib txoj haujlwm yooj yim hauv kev sib raug zoo algebra: Kev Xaiv, Kev Tshaj Tawm, Cartesian khoom , Union , thiab Teeb qhov txawv.

Tsis tas li ntawd, vim li cas kev sib raug zoo algebra tseem ceeb?

Cov kev sib raug zoo algebra yog heev tseem ceeb rau ob peb lub laj thawj: 1. nws muab lub hauv paus tsim nyog rau kev sib raug zoo qauv kev ua haujlwm. Raws li qhov algebra txhais cov txheej txheem kev ua haujlwm rau cov kev sib raug zoo model, ua kev sib raug zoo calculus muab cov lus tshaj tawm qib siab dua rau kev qhia meej kev sib raug zoo lus nug.

Koj nkag siab dab tsi los ntawm kev sib raug zoo algebra piav qhia nrog cov qauv tsim nyog?

Relational Algebra yog cov lus nug txheej txheem siv los nug cov lus database kom nkag mus rau cov ntaub ntawv sib txawv. Tag nrho peb yuav tsum ua yog qhia lub rooj lub npe los ntawm qhov twg peb xav tau cov ntaub ntawv, thiab hauv ib kab lus txib, Relational algebra yuav hla tag nrho cov lus muab los nqa cov ntaub ntawv rau koj.

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