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 โALTER TABLEโ wokushintsha ukwakheka kwetafula, uqambe ithebula ofisa ukulishintsha, umyalo othi โEngezaโ otshela u-Oracle ukuthi wengeza ikholomu entsha, futhi ekugcineni igama lekholomu nesimemezelo sohlobo lwekholomu. .
Inqubo Yokwengeza Ikholomu
Ukubonisa kangcono inqubo, masisebenzise isibonelo sethebula elithi โIkhasimendeโ lapho sifuna ukwengeza ikholomu ye-โDateOfBirthโ ngohlobo lwe-โDATEโ.
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, โN/Aโ) KUSUKA EKHASIMENI;
Lo myalo uzothatha indawo yanoma yimaphi amanani angenalutho kukholamu ye-DateOfBirth ngokuthi โN/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.