Thola okuningi mayelana nokubukwa kwedatha
Ukubukwa kwe- database kukuvumela ukuba unciphise kalula ukubunzima komsebenzi wokugcina womsebenzisi nokunciphisa ikhono labo lokufinyelela idatha equkethwe kuthebhulethi yolwazi ngokunciphisa idatha enikezwe kumsebenzisi wokugcina. Ngokuyinhloko, umbono ubheka imiphumela yombuzo wedatha ukuze uguqule ngokugcwele okuqukethwe kwetafula le-database.
Kungani Usebenzisa Ukubukwa?
Kunezizathu ezimbili eziyinhloko zokuhlinzeka abasebenzisi ukufinyelela kwemininingwane ngokusebenzisa imibono kunokuba banikeze ukufinyelela okuqondile kumatafula e-database:
- Ukubuka kuhlinzeka ngokuphepha okulula, okune-granular . Ungasebenzisa umbono ukuze unciphise idatha umsebenzisi avunyelwe ukuyibona etafuleni. Isibonelo, uma unetafula labasebenzi futhi ufisa ukunikeza abasebenzisi abathile ukufinyelela kumarekhodi wabasebenzi besikhathi esigcwele, ungakha umbono oqukethe lawo marekhodi kuphela. Lokhu kulula kakhulu kunokunye okunye (ukudala nokugcina ithebula lesithunzi) futhi kuqinisekisa ukuthembeka kwedatha.
- Ukubuka kulula ukwenza isipiliyoni somsebenzisi . Ukubukwa kufihla imininingwane eyinkimbinkimbi yamatafula wakho we-database kusuka kubasebenzisi bokuphela abangadingeki ukubababone. Uma umsebenzisi edonsa okuqukethwe kokubuka, ngeke abone amakholomu etafula angakhethi ngombono futhi angase angawaqondi. Lokhu kuvimbela ekudidekeni okubangelwa ngamakholomu angabizwa ngamagama, izihlonzi eziyingqayizivele kanye namakhebula etafula .
Ukudala Ukubuka
Ukudala umbono kubonakala ngokuqondile: umane nje udinga ukudala umbuzo oqukethe imingcele oyifisa ukuyifaka futhi uyibeke ngaphakathi komyalo we-CREATE VIEW. Nasi i-syntax:
DALA VIEW igama lokubuka AS
Isibonelo, uma ufisa ukudala abasebenzi besikhathi esigcwele ngibheke engxoxweni esigabeni esandulele, uzokhipha umyalo olandelayo:
DALA VIEW isikhathi esigcwele AS
Khetha ukhetho lokuqala_name, last_name, employee_id
KUSUKA abasebenzi
LAPHO isimo = 'FT'
Ukushintsha Ukubuka
Ukushintsha okuqukethwe kwombono kusebenzisa i-syntax efanayo ngokudala umbono, kodwa usebenzisa umyalo we-ALTER VIEW esikhundleni somyalo we-CREATE VIEW. Isibonelo, uma ufuna ukwengeza umkhawulo wokubuka okugcwele okufaka inombolo yocingo yomsebenzi emiphumeleni, uzokhipha umyalo olandelayo:
ALTER VIEW isikhathi esigcwele AS
Khetha ukhetho lokuqala_name, last_name, employee_id, ucingo
KUSUKA abasebenzi
LAPHO isimo = 'FT'
Ukususa Ukubuka
Kulula ukususa umbono kusuka ku-database usebenzisa umyalo we-DROP VIEW. Isibonelo, uma ufisa ukususa abasebenzi basezikhathini esigcwele, uzosebenzisa umyalo olandelayo:
DROP VIEW isikhathi esigcwele