Video: Dab tsi yog nrog kev xaiv kos hauv SQL Server?
2024 Tus sau: Lynn Donovan | [email protected]. Kawg hloov kho: 2023-12-15 23:47
SQL Server Saib nrog KUJ OPTION . Views yuav tsim nyob rau hauv SQL Server Nrog KUJ OPTION . Nrog KUJ OPTION yuav ua kom paub tseeb tias tag nrho cov INSERT thiab UPDATE cov lus tau ua tawm tsam qhov kev pom ua tau raws li cov kev txwv hauv WHERE clause, thiab cov ntaub ntawv hloov kho hauv qhov kev pom tseem pom tom qab INSERT thiab UPDATE cov lus.
Tom qab ntawd, ib tug kuj yuav nug, dab tsi yog check xaiv?
Nrog KUJ OPTION ntawm qhov pom. Nrog KUJ OPTION yog ib qho kev xaiv nyob rau ntawm CREATE VIEW nqe lus. Vim tias tsis siv lub ntsiab lus ntawm qhov pom, kab uas tsis ua raws li lub ntsiab lus ntawm qhov kev pom yuav raug tso lossis hloov kho los ntawm qhov pom. Qhov no txhais tau hais tias cov kab tsis tuaj yeem raug xaiv dua los ntawm kev saib.
Ib tug kuj nug, dab tsi yog SQL Server views? Saib yog cov rooj virtual uas tuav cov ntaub ntawv los ntawm ib lossis ntau lub rooj. Nws yog khaws cia rau hauv lub database. A saib tuaj yeem tsim siv cov ntxhuav ntawm tib lub database lossis sib txawv databases. Nws yog siv los siv kev ruaj ntseg mechanism nyob rau hauv lub SQL Server.
Kuj nug, yog dab tsi nrog kev xaiv kos hauv Oracle?
Oracle Nrog KUJ OPTION clause Lub WITH KUJ OPTION clause yog siv rau kev saib updataable los txwv tsis pub cov kev hloov pauv rau qhov pom uas yuav tsim cov kab uas tsis suav nrog hauv cov lus nug. Cov lus hauv qab no tsim ib qho kev pom uas muaj kab raws li qhov xwm txheej ntawm WHERE clause.
Dab tsi yog Schemabinding hauv SQL Server?
SCHEMABINDING yog ib qho kev xaiv uas muaj rau cov khoom hauv T- SQL ntawv uas muaj cov neeg siv kev cai lij choj. Qhia meej tias schema yog khi rau cov khoom siv database uas nws siv. Cov xwm txheej no yuav tiv thaiv kev hloov pauv rau lub schema yog tias lwm cov schema khi cov khoom xa mus rau nws.
Pom zoo:
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