Video: Peb puas tuaj yeem siv ua tiav tam sim rau cov lus xaiv?
2024 Tus sau: Lynn Donovan | [email protected]. Kawg hloov kho: 2023-12-15 23:47
Qhov kev pab cuam tuaj yeem siv EXECUTE IMMEDIATE . EXECUTE IMMEDIATE txhais a xaiv voj mus ua cov kab rov qab. Yog tias xaiv rov qab tsuas yog ib kab, nws tsis tsim nyog siv a xaiv voj.
Li ntawd, Yuav Siv tam sim ua li cas?
Koj tuaj yeem tso ib qho EXECUTE IMMEDIATE nqe lus nrog RETURNING BULK COLLECT INTO hauv ib daim ntawv FORALL. Koj tuaj yeem khaws cov txiaj ntsig ntawm txhua qhov INSERT, Hloov Kho, lossis DELETE cov lus hauv ib pawg ntawm cov khoom sau. Koj tuaj yeem hla subscripted sau cov ntsiab lus mus rau EXECUTE IMMEDIATE nqe lus los ntawm SIV lus.
Tom qab ntawd, lo lus nug yog, peb puas xav tau kev cog lus tom qab ua tiav tam sim? cog lus tsis tas yuav tom qab txhua EXECUTE IMMEDIATE . Tej lus hais ua TSIS TAU xav tau a cog lus ; piv, if koj truncate lub rooj nrog TRUNCATE. Tag nrho cov haujlwm uas tsis tau ua tiav hauv qhov kev hloov pauv tam sim no tau cog lus los yog dov rov qab - tsis yog nqe lus xwb raug tua los ntawm EXECUTE IMMEDIATE.
Hauv qhov no, peb puas tuaj yeem siv ua tiav tam sim hauv Oracle muaj nuj nqi?
Cov EXECUTE IMMEDIATE nqe lus executes dynamic SQL nqe lus los yog tsis qhia npe PL / SQL thaiv. Koj siv tau nws tawm SQL nqe lus uas tsis tuaj yeem sawv cev ncaj qha rau hauv PL / SQL , los yog tsim cov nqe lus nyob qhov twg koj ua tsis paub tag nrho cov npe lub rooj, qhov twg clauses, thiab lwm yam ua ntej.
Vim li cas peb thiaj li siv qhov kev txiav txim tam sim hauv Oracle?
EXECUTE IMMEDIATE pab kev ua tiav ntawm DML lossis DDL nqe lus uas yog tuav raws li txoj hlua thiab tsuas yog ntsuas ntawm lub sijhawm ua haujlwm. Qhov no ua rau ib tus tuaj yeem tsim cov lus hais raws li kev ua haujlwm logic. EXECUTE IMMEDIATE kuj yog tib txoj kev uas koj ua tau ua DDL hauv ib PL / SQL thaiv.
Pom zoo:
Peb puas tuaj yeem siv txuas ntxiv hauv cov lus hloov pauv?
Cov lus txuas ntxiv tsuas yog siv rau cov voj voog, tsis yog rau cov lus hloov pauv. Ib qho txuas ntxiv hauv qhov hloov pauv hauv lub voj ua rau lub voj voog tom ntej. Tau kawg koj yuav tsum tau kaw lub voj (thaum, rau, ua thaum) txhawm rau ua haujlwm txuas ntxiv
Thaum koj reboot koj lub kaw lus lub computer ua raws li pib cov lus qhia khaws cia rau hauv hom kev nco Pawg ntawm cov lus teb xaiv?
Teb Cov Kws Tshaj Lij Tshaj Lij Tshaj Tawm Ib lub khoos phis tawj pib cov lus qhia tau muab khaws cia rau hauv hom nco hu ua Flash. Flash nco tuaj yeem sau rau thiab nyeem los ntawm, tab sis nws cov ntsiab lus tsis raug tshem tawm tom qab lub khoos phis tawj kaw. Lub cim xeeb Flash no feem ntau hu ua BIOS (Basic Input Output System)
Peb puas tuaj yeem muab cov niam txiv cov khoom rau cov khoom me me hauv Java?
Cov chav kawm niam txiv thiab Me Nyuam muaj tib cov ntaub ntawv tus tswv cuab hauv Java. Cov ntaub ntawv sib txawv ntawm Parent class muaj peev xwm tuav nws cov khoom siv raws li nws cov khoom siv me nyuam siv. Cov ntaub ntawv tuav tus menyuam cov khoom siv hauv chav kawm yuav tsis tuaj yeem nkag mus rau cov tswvcuab (kev ua haujlwm lossis kev hloov pauv) ntawm cov menyuam kawm ntawv
Peb puas tuaj yeem siv cov lus npaj rau xaiv cov lus nug hauv Java?
Yuav siv cov lus npaj li cas rau xaiv cov lus nug hauv Java nrog MySQL? Tam sim no koj tuaj yeem tso saib tag nrho cov ntaub ntawv ntawm lub rooj siv Java PreparedStatement. Koj yuav tsum siv txoj kev executeQuery()
Cov cim dab tsi tuaj yeem siv los hloov cov khoom siv hluav taws xob ntawm tus cwj pwm hauv tus xaiv?
1. Asterisk (*): Nws yog siv los hloov 1 lossis ntau tus cim los ntawm tus cwj pwm xaiv. Rau Ej. yog tus cwj pwm uas hloov dynamically, txhua zaus koj qhib ib lub vev xaib tshwj xeeb