Cibiyar sadarwa Data Model

A cibiyar sadarwa data model sauya mafi sauki da kuma bayyana matsayi. A da ginshikin, da cibiyar sadarwa model ne sosai kama da matsayi, shi ma yana da gyara, da cewa shi ne tushen kashi a wadda aka adana mafi muhimmanci bayanai. Tsakanin nodes ake hada ta hanyar Hadin. Kuma nodes located a wannan nisa daga tushen kumburi da nunawa, kamar yadda a cikin matsayi model, matakan. A peculiarity na matsayi model shi ne cewa daga daya kashi zuwa wani ne kawai zai iya zama daya hanya, da kuma a cikin cibiyar sadarwa ba shine al'amarin ba, akwai da dama hanyoyi. A cibiyar sadarwa data model samar da wata dama ga gina karin sifofi na bayanai. Wannan shi ne babban bambanci tsakanin wadannan biyu model.

Domin ya haifar da wani data model ya ganin dangantakar "da yawa ga mutane da yawa" da lokaci daya gyara na data kasance shortcomings a matsayi model, wanda da aka gano a kan lokaci. A cibiyar sadarwa data model dogara ne a kan yin amfani da jadawali ka'idar. Daga wannan ra'ayi, shi yayi dace da wani sabani jadawali. A wannan model, kowane zuriya iya samun wani adadin da kakanninsu. Cibiyar sadarwa database kunshi wani sa na records, kuma ya ce kafa na dangantaka da suke ba tsakanin data records. Iri biyu records, cewa ne m da zuriya, sanin da iri sadarwa. irin sadarwar misali yawanci wakiltar daya misali na m rikodin tare da hada wani da umarnin sa na abubuwa na zuwa yaro shigarwa irin. A karkashin wani sa na fiye gane a matsayin mai suna sa na records, inda daya rikodin irin ayyana mai shi daga cikin sa, da kuma sauran records - wannan sa na members.

A cibiyar sadarwa data model yana da wasu peculiarities. All iri amfani sadarwa dole ne dole a aikin, shi ne "da yawa ga daya", "daya-to-jama'a" ko "daya zuwa daya". A tsarin da aka iyakance ƙ bayyana cewar ga irin wannan dangane da wani irin rikodin m da zuriyar da irin rikodin dole wasu yanayi da ake sadu. Domin sanin dangantakar "da yawa ga mutane da yawa", musamman irin records da aka gabatar, kazalika da biyu daga aikin mahada daga cikin irin "daya zuwa wani jam'i na" da kuma "da yawa-to-daya." Idan dole, ƙarin bayani za a iya kara a cikin rikodi, yin rawar da jijiyoyin sun hadu.

A cibiyar sadarwa model kungiyar dangantakar kullum bayyana dangantakar da irin "daya-to-sa", da cewa shi ne, ma'abũcin daya, amma ya na da yawa qarqashinsu. Daya zai iya buga a matsayin wani misali na wannan ra'ayi kamar yadda "aiki." Ga yana nufin cewa kowane ma'aikaci aiki a wani musamman sashen, amma kowane sashen zai iya da kyau yi aiki a 'yan ma'aikata. A cibiyar sadarwa model type "daya zuwa wani jam'i na" dangantaka tsakanin daban-daban abokai aka aiwatar ta wajen kungiyar dangantakar.

A cibiyar sadarwa model database shafi yin amfani da wadannan ayyukan a kan data:

- Ka tuna, dole ka shigar da bayani a mu database.

- zuwa hada a cikin ƙungiyar hali, cewa an saita tsakanin wadannan takamaiman sadarwa;

- canji, cewa shi ne ya sa miƙa mulki daga daya sa na memba a wani owner;

- karshe, wato, don yin wani gyara daga data;

- tsantsa, wato, don gudanar da ayyukan a kan data karatu.

- cire, cewa shi ne, don a yi mai ma'ana ko ta jiki kau na data;

- sarauta daga rikodin na kungiyar dangantakar, cewa shi ne, don gudanar da keta mahada tsakanin data.

A irin wannan data model yana da musamman fasali domin data magudi da kuma kewayawa daga gare su. Kewayawa naúrar a cikin jadawali model domin kafa records da ka ke so ka nema wani data magudi. Wadannan records suna fiye da ake kira halin yanzu. A cibiyar sadarwa model iya zama ba daga yanzu miƙa mulki ga na gaba misali na yanzu kumburi zuwa wani sabani kokuwa mahada halin yanzu wanda aka gane ta wani rukuni dangantaka. Navigation iya fara tare da wani sabani rikodi.