Mwachizoloŵezi chochepa chodalira ntchito imodzi ndi gawo lina la wina
M'dziko lathano lachidziwitso lazinthu, chikhulupiliro chogwira ntchito chiripo pamene chiwonetsero chimodzi chimaonetsa chidziwitso china mwadongosolo. Kudalira kachabechaka kogwira ntchito ndizodalira zachinsinsi zomwe zimachitika pofotokozera kugwiritsidwa ntchito kogwirizana ndi chikhalidwe kapena chikhumbo cha zikhumbo zomwe zikuphatikizapo chikhalidwe choyambirira.
Zitsanzo za Zovuta Zogwira Ntchito Zovuta
Kudalira kotereku kumatchedwa kuti ndi kopanda phindu chifukwa kungachoke ku luntha. Ngati "mbali" imodzi ndi gawo lina lachilendo, limakhala lochepa. Mbali ya kumanzere ikuwonedwa kuti ndi yodalirika komanso yolondola wodalirika .
- {A, B} -> B ndimadalira kwambiri chifukwa B ndi gawo la A, B. Popeza { A, B} -> B ikuphatikiza B , mtengo wa B ukhoza kudziwika. Ndikofunika kudalira chifukwa chodziwika B chifukwa cha ubale wake ndi A, B. Popeza chikhalidwe cha B chimatsimikiziridwa ndi chikhalidwe cha A , zochitika zina zomwe zimagawana zikhalidwe za A zidzakhala ndizofanana ndi B. Njira inanso yoyikira ndikuti B zonse zimaphatikizidwira mu A , chifukwa chake ndi gawo la A.
- {Employee_ID, Employee_Name} -> Wothandizira_ID ndichinthu chochepa chogwira ntchito kuyambira Employee_ID ndi gawo la {Employee_ID, Employee_Name} .
- N'chimodzimodzi ndi A -> A kapena Employee_ID -> Employee_ID, ndi Employee_Name -> Employee_Name . Izi zonse ndizochepa zokhudzana ndi ntchito.
- Ngati kugwiritsidwa ntchito kogwiritsa ntchito X-> Y, ndi Y ndi gawo la X, izi ndizomwe zimakhala zodalira kwambiri. Ngati Y si chigawo cha X, izi sizomwe zimadalira.