Ukuthola amarekhodi ayimpinda kunoma iyiphi isizindalwazi kungase kube inkinga enkulu engaphazamisa ukuhlangana okuphelele nokuhlanzeka kwedatha etholakalayo, okuletha inselele enkulu kubaphathi besizindalwazi. Amarekhodi ayimpinda angaholela olwazini olungalungile noma oludukisayo, aphumele ezindlekweni ezingadingekile, futhi adale ukungasebenzi kahle phakathi kokugeleza komsebenzi. Bangaphinda bahlanekezele amaqiniso, benze amabhizinisi noma izinhlangano zenze izinqumo ezingalungile ngokusekelwe emininingwaneni yedatha engamanga. Ulimi lwe-Oracle SQL lunezindlela nemisebenzi eminingi engasiza ukuhlonza nokuqeda izimpinda ezinjalo, iqinisekise ubuqotho nokuthembeka kwedatha yakho.
I-Oracle SQL
Ixazululiwe: ukulandelana kokwehla kwe-sql
Impela, ake siqale ngesingeniso esijwayelekile mayelana ne-SQL DROP SEQUENCE.
Isici esibalulekile sokuphathwa kwesizindalwazi ku-Oracle SQL ukudalwa nokulawulwa kokulandelana. Uma usebenzisana nezizindalwazi ezinkulu, ukulandelana kunikeza indlela yokukhiqiza okuzenzakalelayo kwezihlonzi ezihlukile. Njengoba nje sidinga ukudala lokhu kulandelana ukuze sisekele imisebenzi yethu egciniwe, sidinga futhi ukukususa ngezinye izikhathi. Ku-Oracle SQL, lokhu kufinyelelwa ngokusebenzisa i-SQL DROP SEQUENCE.
Kodwa-ke, ukususwa kwalokhu kulandelana kufanele kwenziwe ngokucophelela, njengoba kungase kube nomthelela ekusebenzeni kwezinhlelo ezikhona ezizisebenzisayo.
Kuxazululiwe: khombisa wonke amathebula
Emhlabeni ophithizelayo we-Oracle SQL, umsebenzi owodwa ongase uzithole udinga ukuwenza isenzo sokubonisa wonke amatafula. Lokhu kusebenza kuwubuhle kodwa kusebenza ngendlela emangalisayo, akufani kakhulu nempahla ekhethwe ngokucophelela emzileni wezindiza wemfashini. Amathebula ku-SQL awumgogodla ogcina idatha yakho, efana nengubo ethungwe kahle eyethula oyigqokile ekukhanyeni okungcono kakhulu. Ngokuchitha isikhathi esincane uqonda ukuthi ungabonisa kanjani wonke amatafula, ungathola umbono obanzi wesizindalwazi sakho, ngendlela efanayo ukubuka okujulile kwekhabethe kungakhuthaza inhlanganisela emangalisayo yezingubo.
Kuxazululiwe: phrinta
Phrinta isici esiyisisekelo sohlelo ku-Oracle SQL kanye nomthelela omkhulu kumathrendi emfashini. Ukuphrinta kudlala indima ebalulekile ekwethulweni kwedatha, ekulolongeni indlela ulwazi oluvezwa futhi luhunyushwe ngayo. Kusukela emhlabeni wokuphathwa kwedathabhesi kuya emigwaqweni yaseParis naseMilan, ukuphrinta kuqophe indlela ebalulekile- indlela ehlukahlukene njengezilimi zokuhlela okuyingxenye yazo kanye nezitayela zemfashini ezikhuthazayo.
Kuxazululiwe: hlola igama lesizindalwazi
Ingabe ufuna igama lesizindalwazi sokuhlola elithembekile nelinembile? Ungabheki ngaphezu kokuthi Hlola Igama Lesizindalwazi. Isizindalwazi sethu sibuyekezwa njalo ngedatha yesheke yakamuva, ukuze uqiniseke ukuthi uthola ulwazi lwakamuva kakhulu.
Ixazululiwe: umbuzo wenguqulo ye-db
Kubalulekile ukuhlala unolwazi ngenguqulo yesofthiwe ye-Oracle Database esisebenza nayo njengoba ithinta kakhulu ukusebenza nokusebenza kwamakhodi nemibuzo esiyisebenzisayo. Lesi sihloko sidingida izindlela zokubuyisa inguqulo ye-Oracle Database. Injini ye-Oracle SQL isebenzisa izici eziningi nemisebenzi engenza kube lula kakhulu inqubo yokubuyisa inguqulo. Lesi sihloko sizohlomisa umfundi ngolwazi kanye namazwibela ekhodi ayisisekelo, nokho abalulekile adingekayo ukuze kutholwe inguqulo ye-Oracle Database.
I-Oracle Database iwuhlelo oluqinile lwe-otho-relational database management system (RDBMS) olukhiqizwe yi-Oracle Corporation. I-Oracle Database ibizwa ngokuthi i-Oracle RDBMS noma i-Oracle nje. Ngokusebenzisa i-Oracle SQL, abathuthukisi bangaphatha inani elikhulu ledatha futhi basebenzise izixazululo eziqhutshwa idatha.
KHETHA * KUSUKA ku-v$version;
Umyalo ongenhla unikeza inguqulo yesizindalwazi se-Oracle oxhumeke kuso. I-`v$version` iwukubuka okugxilile okunikeza imininingwane yenguqulo yezingxenye ezihlukene zesenzakalo se-Oracle, okuhlanganisa inguqulo Yedathabhesi ye-Oracle.
Ake siphule umyalo:
`KHETHA *` - Le ngxenye yombuzo we-Oracle SQL ikhuthaza iseva ukuthi ikhethe zonke izinkambu (amakholomu) atholakala kuthebula elishiwo, elithi `v$version` kulesi simo.
`KUSUKA ku-v$version;` - Le ngxenye yomyalo we-SQL icacisa ukubuka okugxilile kwesizindalwazi se-Oracle okudingeka sikubuze ukuze sibuyise imininingwane yenguqulo.
Kuxazululiwe: vula umsebenzisi
I-Oracle SQL, isizindalwazi esinamandla sokuphatha kanye nolimi lokuhlela, lusetshenziswa kabanzi ezinhlanganweni ezahlukahlukene ukwenza imisebenzi yekhompyutha eyinkimbinkimbi. Ukuphathwa kwedatha kuba lula futhi kube lula ezinkampanini ze-IT nezinhlangano zebhizinisi. Le ndatshana ingena endaweni ye-Oracle SQL, iletha ngokukhethekile inqubo yokuvula idatha yomsebenzisi, ebalulekile ekubhekeni kokuphepha nokuphathwa kwedatha. Incazelo eningilizayo, yesinyathelo nesinyathelo izocaciswa ukuze kuhlinzekwe ngokuqondiswa komfundi.
Kuxazululiwe: shintsha i-nls_date_format unomphela
Amapharamitha e-NLS kusizindalwazi se-Oracle adlala indima ebalulekile ekuphatheni izinhlelo zokusebenza zamazwe ngamazwe. Imingcele enjalo ivame ukusetshenziselwa ukubusa kokubili ulimi olusetshenziselwa imilayezo kanye nendlela i-Oracle SQL ephatha ngayo idatha nokufometha kwedethi. Ipharamitha eyodwa yenani elibalulekile `nls_date_format`, elawula ukuthi amanani edethi aboniswa kanjani phakathi nezikhathi zakho ze-SQL. Ezimweni eziningi, abaphathi besizindalwazi nabathuthukisi bangase babe nesidingo sokushintsha `nls_date_format` unomphela ukuze ivumelane nezimfuneko ezithile.