Dab tsi yog database schema thiab piv txwv?
Dab tsi yog database schema thiab piv txwv?

Video: Dab tsi yog database schema thiab piv txwv?

Video: Dab tsi yog database schema thiab piv txwv?
Video: Cia ua ib zaj dab neeg karaoke 2024, Kaum ib hlis
Anonim

Kev txhais ntawm piv txwv : Cov ntaub ntawv khaws cia hauv database ntawm lub sijhawm tshwj xeeb ntawm lub sijhawm hu ua piv txwv ntawm database . Database schema txhais cov lus tshaj tawm sib txawv hauv cov lus uas yog rau ib qho tshwj xeeb database ; tus nqi ntawm cov kev hloov pauv ntawm lub sijhawm no yog hu ua piv txwv ntawm qhov ntawd database.

Tsis tas li ntawd, dab tsi yog qhov schema hauv database?

Database schema . Lub sij hawm " schema " yog hais txog lub koom haum ntawm cov ntaub ntawv raws li ib tug blueprint ntawm yuav ua li cas lub database yog tsim (sib faib ua database rooj nyob rau hauv rooj plaub ntawm kev sib raug zoo databases ). Lub ntsiab txhais ntawm a database schema yog ib txheej ntawm cov qauv (cov kab lus) hu ua integrity constraints imposed on a database.

Ib sab saum toj no, qhov txawv ntawm database schema thiab piv txwv yog dab tsi? Lub ntsiab qhov sib txawv ntawm schema thiab piv txwv yog tias schema yog ib qho kev pom ntawm qhov database , thaum lub piv txwv yog cov ntaub ntawv khaws cia hauv database ntawm lub sijhawm tshwj xeeb. Cov database yog ib qho kev sau cov ntaub ntawv. DBMS yog software program uas pab khaws thiab tswj cov ntaub ntawv hauv ntau yam databases.

Tom qab ntawd, dab tsi yog qhov piv txwv hauv database?

A database piv txwv yog ib txheej ntawm lub cim xeeb uas tswj database cov ntaub ntawv. A database yog ib txheej ntawm cov ntaub ntawv lub cev ntawm disk tsim los ntawm CREATE DATABASE nqe lus. Cov piv txwv tswj nws cov ntaub ntawv cuam tshuam thiab ua haujlwm rau cov neeg siv cov database.

Koj txhais li cas los ntawm schema hauv DBMS?

Ib database schema yog lub cev pob txha uas sawv cev rau qhov kev xav pom ntawm tag nrho cov ntaub ntawv. Nws txhais tau li cas cov ntaub ntawv raug teeb tsa thiab kev sib raug zoo ntawm lawv li cas yog cuam tshuam. Nws tsim tag nrho cov kev txwv uas yog yuav tsum tau siv rau ntawm cov ntaub ntawv.

Pom zoo: