Izigqibo zichonga amaxabiso anikwe kwezinye iimpawu
I-determinant kwisitheyibhile sedatha iyimpawu engasetyenziselwa ukuchonga iimpawu ezinikezelwe kwezinye iimpawu kumqolo ofanayo. Ngaloo nkcazo, nayiphi na ikona ephambili okanye ukhetho lomgqatswa luyi-determinant, kodwa kunokuba kubekho izigqibo ezingenasisiseko okanye izitshixo zabaviwa.
Umzekelo, inkampani inokusebenzisa itafile ngeempawu , , kunye .
| Employee_id | Igama lokuqala | Ifani | Umhla wokuzalwa |
|---|
123
| Megan | Ntsundu | 01/29/1979 |
| 234 | UBen | Wilder | 02/14/1985 |
| 345 | Megan | Chowdery | 2/14/1985 |
| 456 | Charles | Ntsundu | 07/19/1984 |
Kule meko, inkundla inquma iindawo ezintathu ezisele. Igama lemihlaba alinqumi kuba i-firm ingaba nabasebenzi ababelana ngegama lokuqala okanye igama elifanayo. Ngokufanayo, i- insimu ayinqumi okanye igama lemihlaba kuba abasebenzi bangabelana ngolunye usuku lokuzalwa.
Ubudlelwane obuqingqiweyo kwiiKhowudi zeDatabase
Kulo mzekelo, ngumxhasi, ukhetho lomviwa, kunye neyona nto ephambili. Ingundoqo yokhetho kuba xa i- database yonke isesha 234, umqolo oqulethe ulwazi malunga noBen Wilder ubonakala kwaye akukho enye irekhodi iboniswa. Omnye ukhetho lomviwa luyenzeka xa ukhangela i database ngokufumana ulwazi kwiintsika ezintathu; , kunye , ebuye ithola umphumo ofanayo.
Kwakhona, uqinisekisiwe ukuba uyahluke kule tafile, kungakhathaliseki ukuba bangaphi abanye abasebenzi abakhoyo, ngokuchasene nolwazi kwezinye iikholomu.