Kuxazululiwe: engeza ikholomu

Impela, Nakhu sihamba!

I-Oracle SQL iwulimi olusebenza kahle kakhulu olunikeza inkundla yokusebenzisa imiyalo ye-SQL kusizindalwazi se-Oracle. Isetshenziselwa ukuphatha kanye nokukhohlisa izinto ze-schema ezifana nokudalwa kwesizindalwazi, ukudala ukubuka, ukudala ukulandelana, ukudalwa kwegama elifanayo, nokunye ukusebenza okuyinkimbinkimbi. Kulesi sihloko, sizoxoxa ngokusebenza okukodwa okunjalo okuyisisekelo- ukwengeza ikholomu etafuleni ku-Oracle SQL.

ALTER TABLE table_name
ENGEZA uhlobo_lwekholomu_yegama;

Lona umyalo oyisisekelo ongawusebenzisa ukwengeza ikholomu kuthebula elikhona. I-syntax ihlanganisa umyalo othi โ€œALTER TABLEโ€ wokushintsha ukwakheka kwetafula, uqambe ithebula ofisa ukulishintsha, umyalo othi โ€œEngezaโ€ otshela u-Oracle ukuthi wengeza ikholomu entsha, futhi ekugcineni igama lekholomu nesimemezelo sohlobo lwekholomu. .

Inqubo Yokwengeza Ikholomu

Ukubonisa kangcono inqubo, masisebenzise isibonelo sethebula elithi โ€œIkhasimendeโ€ lapho sifuna ukwengeza ikholomu ye-โ€œDateOfBirthโ€ ngohlobo lwe-โ€œDATEโ€.

Isinyathelo 1: Hlola Isakhiwo Samanje

Okokuqala, kuwumkhuba omuhle ukuhlola isakhiwo samanje setafula lakho.

Ikhasimende le-DESCER;

Lokhu kuzobonisa isakhiwo samanje sethebula elithi "Ikhasimende".

Isinyathelo sesi-2: Engeza Ikholomu Entsha

Okulandelayo, uzokhipha umyalo wokwengeza ikholomu entsha.

ALTER TABLE Ikhasimende
ENGEZA Idethi Yokuzalwa;

Ukusebenza ne-Oracle SQL Libraries

I-Oracle SQL inosekelo olubanzi lomtapo wezincwadi, okwenza kube lula ukwenza imisebenzi eyinkimbinkimbi. Ayihlobene ngokuqondile nokwengeza amakholomu, amalabhulali afana ne-UTL_FILE avumela ukufunda nokubhalela amafayela, i-UTL_HTTP ishayela ama-URL e-HTTP nawe-HTTPS, futhi i-DBMS_SQL ivumela ukusebenza kwe-SQL okuguquguqukayo.

Imisebenzi ku-Oracle SQL

Imisebenzi ingenye ingxenye ebalulekile ye-Oracle SQL esingayisebenzisela imisebenzi ethile kusizindalwazi sethu. Umsebenzi owodwa ovame ukusetshenziswa lapho wengeza amakholomu umsebenzi we-NVL. Lo msebenzi usetshenziselwa ukufaka inani elishiwo esikhundleni samanani angenalutho.

KHETHA I-NVL(DateOfBirth, โ€œN/Aโ€) KUSUKA EKHASIMENI;

Lo myalo uzothatha indawo yanoma yimaphi amanani angenalutho kukholamu ye-DateOfBirth ngokuthi โ€œN/Aโ€.

Njengoba sesibonile, ukwengeza ikholomu kusizindalwazi se-Oracle kuhilela ukusebenzisa imiyalo eyisisekelo ye-SQL nokuqonda ukuthi isebenza kanjani. Ngemitapo yolwazi ye-Oracle SQL nemisebenzi, singenza isizindalwazi sethu sisebenze kahle futhi siqine. Ulwazi lwazo zonke lezi zici lunomthelela ekulawulweni kwesizindalwazi ngendlela efanele, ukwandisa ukukhiqiza, kanye nokunciphisa isikhathi sokuphumula.

Okuthunyelwe okuhlobene:

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