Model data evela kwenye

Izinto zifumaneka rhoqo kakhulu ulwalamano olunjalo, leyo kuthiwa oluneqela elinegunya. Ngokuqhelekileyo oku kuza ku nolwalamano olunjalo, njengoko "part-wonke", ubuhlobo ngaphantsi okanye iintlobo zobudlelwane. Izinto ezikhoyo kulwalamano efanayo, yakha umthi, ekuthiwa igrafu ngqo, oko kukuthi, ukuba enekona enye kuphela hayi subordinated kuyo nayiphi na enye enekona. Lendawo ibizwa ngokuba ingcambu somthi. Unxibelelwano phakathi kwezinye iindawo kuphunyezwa ngolu hlobo lulandelayo: naziphi na incopho kuxhomekeke kuphela kulowo ibekwe ngaphezu kwayo, phezulu. Ngokwengqiqo, imodeli data evela kwenye into bendiqonda iseti neendidi zeerekhodi ukuba iintlobo obuchopho ezinxulumene ibe single okanye imithi ezimbalwa ngamnye. Kulo mzekelo, zonke iindidi neentambo akhiwa ngokwezi "omnye ukuya ezininzi", yaye igrafu bubonakaliswe iintolo. Kubonakala ukuba umfuziselo data oluneqela unalo olu hlobo ubudlelwane phakathi kwezinto, bobabini emthini usapho, Noko ke, elinye ngaphandle: kukho mnye kuphela isifundo esingundoqo into nganye ilawulwe. Oko kukuthi, ukuba onjalo imodeli data kuvunyelwa ukuba babe ngababini kuphela iintlobo zonxibelelwano phakathi izinto database, "enye ukuya kwenye" okanye "ezininzi". Le database oluneqela in umongo isiseko data yeNavigeyishini, oko kukuthi, ukufikelela kunokwenzeka kuphela ngoncedo yonxulumano ezichazwe ngaphambili.

Ukuba wenziwe isiganeko yokulinganisa, unxibelelwano ngokuqhelekileyo ifuna "kakhulu ezimbalwa." Ukuba ususe le nciphiso, unako ukunika isisombululo enjalo, njengoko phindwa kwezakhiwo. Noko ke, kukho ukunqongophala phindo bezinto: zingavela na ukungangqinelani kwengcaciso. imodeli data oluneqela zinezibonelelo ezifana nokuqinisekisa ukufikelelwa lula ecaleni yamakhonknco ezichazwe ngenxa yokukhangela yayo indalo. Noko ke, kukho naye kunye nobubi. Bona enxulumene ukungabikho ngqongqo xa imodeli data, ngokukodwa ngokubhekisele nakwenzeka ubukho into ngabazali eziliqela, kwakunye nokungakwazi afumane ufikelelo ngqo le data. Oku ibe engafanelekanga phantsi kwemiqathango rhoqo imibuzo ukuba ngaphambili azizange izicwangciso. Umfuziselo oluneqela database elinye ethile. kuxhomekeke kwinto yokuba retrieval ulwazi ukusuka kumanqanaba asezantsi oluneqela ezingenako ukuthunyelwa nge ezalathelwe akhiwe ngasentla.

Njengoko ezi units inkcazelo esisiseko ngendlela imodeli oluneqela elinegunya le icandelo kunye entsimini. Phantsi Ifildi yeengcombolo athathiweyo ukumisela iyunithi incinane ayahlukahlukenanga lwe data ekhoyo kumsebenzisi. Ukuze ziqwempu athathiweyo ukuqinisekisa ukuba hlobo kunye ingxenye umzekelo. Uhlobo ingxenye yingqokelela ebizwe amasimi iindidi zedata, apho sakhiwa. Umzekelo ingxenye wabumba amaxabiso athile ezithile emasimini. Le modyuli yedata oluneqela elinegunya, njengoko kukhankanyiwe ngasentla, senziwa imilo nesakhiwo sedata kwigrafu. Xa siqwalasela oku kwinqanaba le mbono, kuba ityala eyodwa imodeli womnatha kuphela. In imodeli oluneqela eziphezulu bahambelana uhlobo kwicandelo kunye jike - uhlobo unxibelelwano kwi "umzali nomntwana". Kukho ulawulo olungqongqo, kwi abangakwaziyo-umzukulwana abe mnye kuphela-mkhulu. Ngokuqhelekileyo, le modeli ofana grafu ndenzile eqhagamshelwe abe kwisakhiwo somthi, leyo eye onke amacandelo. Ulwakhiwo oluneqela uhlobo database uquka iseti oda imithi. Umfuziselo ngokwayo ngumthi, kwinqanaba eliphezulu nto leyo enye into ephambili ibekwe ngumphakamo wesibini izinto kwinqanaba lesibini, eyesithathu - nowesithathu, njalo-njalo.

Ukususela kule nto, ungakwazi ukufumana umbono ezinye yintoni eyenza oluneqela elinegunya isakhiwo data.