Oracle DML yog dab tsi?
Oracle DML yog dab tsi?

Video: Oracle DML yog dab tsi?

Video: Oracle DML yog dab tsi?
Video: What is Database & SQL? 2024, Kaum ib hlis
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Oracle DML Nqe lus. DML (Data Manipulation Language) cov nqe lus yog cov ntsiab lus hauv SQL lus uas yog siv rau kev muab cov ntaub ntawv rov qab thiab tswj xyuas. Siv cov nqe lus no koj tuaj yeem ua haujlwm xws li: ntxiv kab tshiab, hloov kho thiab tshem tawm kab uas twb muaj lawm, sib koom ua ke cov rooj thiab lwm yam.

Cov lus nug tseem yog, DML thiab DDL yog dab tsi hauv Oracle?

DML stands rau Data Manipulation Language. Cov nqe lus SQL uas muaj nyob hauv DML chav kawm yog INSERT, UPDATE thiab DELETE. Cov ntaub ntawv txhais lus ( DDL ) yog siv los txhais cov qauv database. Txhua CREATE, DROP thiab ALTER cov lus txib yog cov piv txwv ntawm DDL SQL lus.

Ib yam li ntawd, hom DML yog dab tsi? Muaj ob hom DML : txheej txheem, nyob rau hauv uas tus neeg siv qhia tau hais tias yuav tsum tau cov ntaub ntawv dab tsi thiab yuav ua li cas kom tau nws; thiab nonprocedural, nyob rau hauv uas tus neeg siv qhia tsuas yog dab tsi cov ntaub ntawv yog xav tau.

Hais txog qhov no, yog xaiv DML nqe lus hauv Oracle?

Hauv kev coj ua tab sis, qhov kev sib txawv no tsis yog ua thiab Xaiv yog dav suav hais tias yog ib feem ntawm DML . Raws li qhov piv txwv ntawm qhov tsis muaj qhov sib txawv, qhov Oracle 11.2 Cov Lus Qhia Qhia suav nrog SELECTS li DML raws li nram no: Data manipulation language ( DML ) nqe lus query lossis manipulate cov ntaub ntawv hauv cov khoom schema uas twb muaj lawm.

Puas yog DML xav tau kev cog lus?

DDL yog nws pib cog lus thiab koj yuav tsum tsis txhob muab cov lus cog tseg vim nws cuam tshuam rau cov qauv lossis cov ntaub ntawv meta hauv cov ntaub ntawv thaum nyob hauv DML, nws cuam tshuam rau cov ntaub ntawv. Yog vim li ntawd, DML xav tau kev cog lus lossis rov qab kom zoo ib yam lossis thim rov qab koj cov kev hloov pauv.

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