Network Data Model

Nemambure date womuenzaniso unotsiva zvikuru nyore uye zvakajeka hierarchical. At paro, nemambure womuenzaniso zvakafanana zvikuru vakuru vakuru, uyewo ane zvinoriumba, kuti ndiwo mudzi chinhu umo inochengeterwa rinokosha ruzivo. Between nodes ikashandiswa kuburikidza linkages. Zvino nodes chiri panzvimbo imwechete chinhambwe kubva pamudzi raiva pedyo nebundu yokuumba, sapamazuva hierarchical womuenzaniso, nhanho. The peculiarity of hierarchical womuenzaniso yakanga kuti kubvira mumwe chinhu kune umwe kunogona chete kuva rimwe nzira, uye mambure hazvina kudaro, pane pakutengeserana dzakawanda. Nemambure date womuenzaniso chinopa mukana kuvaka mamwe zvivako dzakaoma kuti mashoko. Izvi ndizvo musiyano mukuru pakati izvi zvivezwa maviri.

Kuti pave umboo muenzaniso kwaiva kuzadziswa ukama "vazhinji zhinji" pamwe mawa nokururamiswa yaivapo zvikanganiso zviri hierarchical womuenzaniso, zvange kuzivikanwa pamusoro nguva. Nemambure date womuenzaniso kunobva pakushandisa girafu dzidziso. Kubva pfungwa iyi maonero, yakafanana ive zvemasanga girafu. In womuenzaniso ichi, mumwe muzukuru anogona kuva chero nhamba madzitateguru. Network Database rine yakatarwa zvinyorwa, uye akati kuisa ukama kuti varipo pakati date zvinyorwa. Two mhando marekodzi, kuti ndiye tateguru uye muzukuru, kuona marudzi kubatana. mhando kutaurirana Somuenzaniso inomiririra imwe inoonekwa tateguru achinyora pamwe nechekuita mukugarisana ane akarayira yakatarwa zvinhu kuva mwana kupinda mhando. Pasi seti nevakawanda kunzwisisa somunhu ainzi yakatarwa zvinyorwa, apo mumwe rekodhi mhando wakarondedzera muridzi yakatarwa, uye zvimwe zvinyorwa - ichi yakatarwa nhengo.

Nemambure Data womuenzaniso une zvimwe dzose. mhando dzose vakashandisa kwokubatana vanofanira hazvo chadzo, ndiko kuti "vazhinji mumwe", "mumwe-kuti-vazhinji" kana "mumwe nomumwe". The muenzaniso iri shoma nechomukati akaratidza okuti uyu mhando maererano imwe mhando nezvenhoroondo tateguru uye wedzinza mhando pakunyora hazvo zvimwe zvinhu zviri zvakasangana. Kuti tizive ukama "vazhinji zhinji", rinokosha mhando zvinyorwa kwave vakasuma, uyewo peya dzichipfekeka kubatana ari fomu "mumwe munhu muzvizhinji kuti" uye "vazhinji-to-mumwe." Kana zvakakodzera, mamwe mashoko inogona kuwedzerwa zviri kurekodha, achiita basa nemarunda.

Kazhinji nemambure womuenzaniso boka ukama kutsanangura ukama mhando "imwe-kuti-yakatarwa", kureva, muridzi mumwe, asi ane zvakawanda pasi. Mumwe anogona kumbotipa muenzaniso mafungiro ichi se "basa." Pano zvinoreva kuti mushandi mumwe anoshanda chero Kunyanya dhipatimendi, asi dhipatimendi ose zvinogona basa vashandi vashoma. Nemambure wokuenzanisira mhando "imwe mumwe muzvizhinji kuti" ukama pakati siyana masangano ari chinozoiswa pachishandiswa boka ukama.

Nemambure womuenzaniso Database kunosanganisira kushandisa zvinotevera remapazi pamusoro date:

- Yeuka, unofanira kupinda mashoko Database yedu;

- kuti zvinyorwe muboka mafungiro, zvinoiswa pakati izvi chaizvo kutaurirana;

- chinja, kureva kuti kuchinja kubva iine nhengo kune mamwe muridzi;

- update, kureva kuti chero dikidiki mashoko;

- mushoma, kureva kuti vaite mabasa pamusoro date kuverenga;

- kubvisa, kureva, kuti zvine musoro kana utano kubviswa mashoko;

- ushe kubva nhoroondo boka ukama, ndiko, kuti vaite kutyora kubatana pakati mashoko.

Zvakadaro date womuenzaniso anonyanya zvinhu kuti mashoko evanhu uye wekushandisa pakati pavo. Rwendo dzaishandiswa mune girafu muenzaniso pakagadzwa zvinyorwa uko zvaunoda kushandisa imwe date evanhu. Zvinyorwa izvi zviri anowanzonzi ano. Nemambure womuenzaniso anogona kuvapo kubva kuitika kuchinja unotevera inoonekwa ano raiva pedyo nebundu mumwe zvemasanga vertex linked ano iyo yakazadzika neboka ukama. Navigation anogona kutanga imwe zvemasanga yakarekodwa.