Ubuhlobo obunye nomunye buyingxenye ebalulekile yokwakha i-database
Ubuhlobo bomuntu ngamunye kuya kwenzeka uma kukhona irekhodi elilodwa etafuleni lokuqala elihambisana nerekhodi elilodwa kuthebula elihlobene. Isibonelo, izakhamuzi zase-US zinenani lenombolo yezokuphepha. Kukhona inombolo eyodwa kuphela eyabelwe umuntu ngamunye, ngakho-ke, umuntu akakwazi ukuba nezinamba eziningi.
Nasi esinye isibonelo usebenzisa amatafula amabili ngezansi. Amatafula abe nobuhlobo obulodwa kuya komunye ngoba umugqa ngamunye etafuleni lokuqala uhlobene ngqo nomunye umugqa kuthebula lesibili.
| Inombolo yomsebenzi | Igama | Isibongo |
| 123 | Rick | Rossin |
| 456 | Rob | I-Halford |
| 789 | Eddie | Henson |
| 567 | Amy | Isibopho |
Ngakho inani lemigqa emagameni ezisebenzi zetafula kufanele lifanane nenani lemigqa etafuleni lendawo yokusebenza.
| Inombolo yomsebenzi | Isikhundla | Ifoni ye-Ext. |
| 123 | Hlanganisa | 6542 |
| 456 | Umphathi | 3251 |
| 789 | Hlanganisa | 3269 |
| 567 | Umphathi | 9852 |
Olunye uhlobo lwemodeli ye- database yibuhlobo obuningi kuya kokuningi. Ukusebenzisa ithebula elingezansi ungabona ukuthi uRob Halford, ungumphathi, ngakho ubuhlobo bakhe nesimo nendawo eyodwa ngoba kule nkampani umuntu unendawo eyodwa kuphela. Kodwa isikhundla sikamenenja sihlanganisa abantu ababili, u-Amy Bond noRob Halford, ubuhlobo obuningi kuya phezulu. Isikhundla esisodwa, abantu abaningi.
Funda kabanzi mayelana nobudlelwano beDatabases, amaKhokhi angaphandle, ama-JOINs kanye nemidwebo ye-ER .