Video: Peb puas tuaj yeem siv DDL hauv cov txheej txheem khaws cia?
2024 Tus sau: Lynn Donovan | [email protected]. Kawg hloov kho: 2023-12-15 23:47
Koj siv tau nkaus xwb DDL COMMENT nqe lus hauv a khaws cov txheej txheem . Koj tsis tuaj yeem hais qhia DML COMMENT nqe lus, uas txwv tsis pub siv SQL embedded, mus nqa cov lus rau cov khoom siv database, txhua kab ntawm lub rooj, thiab cov kev txwv.
Ib yam li ntawd, tib neeg nug, peb puas tuaj yeem siv DDL hauv cov txheej txheem?
DDL cov lus tsis pub nyob rau hauv Cov txheej txheem (PLSQL BLOCK) PL/SQL khoom yog precompiled. Ntawm qhov tod tes, DDL (Data Definition Language) cov lus zoo li CREATE, DROP, ALTER commands thiab DCL (Data Control Language) cov lus zoo li GRANT, REVOKE ua tau hloov cov dependencies thaum lub sij hawm ua tiav ntawm qhov kev pab cuam.
Tsis tas li, peb puas tuaj yeem sau DDL nqe lus hauv kev ua haujlwm hauv Oracle? Tsis muaj DDL tso cai: A muaj nuj nqi hu los ntawm sab hauv a SQL lus yog txwv tsis pub DDL vim DDL teeb meem ib tug implicit cog lus. Koj tsis tuaj yeem tawm ib qho twg DDL cov ntsiab lus los hauv ib PL/SQL muaj nuj nqi . Kev txwv tsis pub muaj kev txwv: Koj siv tsis tau a muaj nuj nqi nyob rau hauv lub check constraint ntawm tsim lub rooj DDL lus.
Tsis tas li ntawd, DDL tuaj yeem siv hauv PL SQL?
2 Teb. Raws li nws hais nyob rau hauv cov ntaub ntawv: Tsuas yog dynamic SQL tau ua raws li cov lus qhia hauv qab no PL / SQL ntawv program units: Data definition lus ( DDL ) cov nqe lus xws li CREATE, DROP, GRANT, thiab REVOKE.
Peb puas tuaj yeem tsim cov lus hauv cov txheej txheem khaws cia?
Hauv a khaws cov txheej txheem koj tuaj yeem tsim a rooj los yog saib. Cov rooj tau ua ib ntus, hauv - nco rooj (saib CREATE TABLE ). Txawm li cas los xij, koj tsis tuaj yeem xa mus rau qhov ntawd rooj los yog saib hauv tib yam khaws cov txheej txheem . Cov Tsim txheej txheem / ALTER txheej txheem nqe lus sau tag nrho SQL SELECT thiab DML nqe lus.
Pom zoo:
Peb puas tuaj yeem siv kev lag luam hauv cov txheej txheem khaws cia?
Yog tias peb muaj ntau tshaj ib nqe lus SQL hauv kev ua tiav hauv cov txheej txheem khaws cia thiab peb xav rov qab hloov pauv ib qho ntawm SQL nqe lus nyob rau hauv rooj plaub uas muaj qhov yuam kev tshwm sim vim yog ib qho ntawm SQL nqe lus, peb tuaj yeem siv kev hloov pauv hauv cov txheej txheem khaws cia
Peb puas tuaj yeem siv DDL nqe lus hauv cov txheej txheem hauv Oracle?
DDL nqe lus tsis raug tso cai nyob rau hauv Cov Txheej Txheem (PLSQL BLOCK) PL/SQL cov khoom yog precompiled. Ntawm qhov tod tes, DDL (Data Definition Language) cov lus xws li CREATE, DROP, ALTER commands thiab DCL (Data Control Language) cov lus zoo li GRANT, REVOKE tuaj yeem hloov pauv qhov kev vam meej thaum lub sijhawm ua tiav ntawm qhov program
Peb puas tuaj yeem dhau array rau cov txheej txheem khaws cia hauv SQL Server?
Tsis muaj kev txhawb nqa rau array hauv sql server tab sis muaj ntau txoj hauv kev uas koj tuaj yeem hla kev sau mus rau qhov khaws cia proc
Koj tuaj yeem siv cov txheej txheem khaws cia thiab lossis ua rau cov ntaub ntawv no li cas?
Peb tuaj yeem ua tiav cov txheej txheem khaws cia thaum twg peb xav tau nrog kev pab los ntawm exec hais kom ua, tab sis qhov tshwm sim tsuas yog raug tua thaum twg ib qho kev tshwm sim (ntxig, rho tawm, thiab hloov tshiab) raug rho tawm haujlwm ntawm lub rooj uas txhais tau hais tias. Cov txheej txheem khaws cia tuaj yeem coj cov kev nkag tsis tau, tab sis peb tsis tuaj yeem hla tsis tau raws li kev nkag mus rau qhov tshwm sim
Peb puas tuaj yeem siv cov txiaj ntsig hauv cov txheej txheem khaws cia?
Trigger: Cov txiaj ntsig tuaj yeem ua tiav ntawm qhov kev txiav txim siab ntawm lub rooj nyiam, hloov tshiab, rho tawm, lossis hloov kho. Cov txheej txheem khaws cia: Cov txheej txheem khaws cia tsis tuaj yeem raug hu los ntawm lub luag haujlwm vim tias cov haujlwm tuaj yeem raug hu los ntawm cov lus xaiv thiab Cov Txheej Txheem Khaws tsis tuaj yeem hu los ntawm