Sebenzisa imidwebo ye-ER ukuze ufanise ubudlelwane phakathi kwezinhlangano zamadatha
I-entity-relation diagram ifomu elicacile elibonisa ukuhlobana phakathi kwamabhizinisi ku-database . Imidwebo ye-ER ngokuvamile isebenzisa izimpawu ukumela izinhlobo ezintathu zolwazi: izinhlangano (noma imibono), ubudlelwane nezici. Emibhalweni ejwayelekile ye-ER imidwebo, amabhokisi asetshenziselwa ukumela izinhlangano. Amadayimane asetshenziselwa ukumela ubudlelwane, futhi ama-ovals asetshenziselwa ukumela izimfanelo.
Nakuba ku-iso elingakafundiwe, imidwebo-ubudlelwane bobudlelwane bungabonakala buyinkimbinkimbi, kubabukeli abanolwazi, basiza abasebenzisi bebhizinisi ukuthi baqonde izakhiwo ze- database ezingeni eliphezulu ngaphandle kokuhambisana nemininingwane.
Abaqambi be-database basebenzisa imidwebo ye-ER yokufanisa ubudlelwane phakathi kwama-database entweni ecacile. Amaphakheji amaningi we-software anezindlela ezizenzakalelayo zokukhiqiza imidwebo ye-ER kusuka kumininingwane yolwazi ekhona.
Cabanga ngesibonelo se-database equkethe ukwaziswa kwabakhileyo edolobheni. Umdwebo we-ER oboniswe esithombeni esihambisana nalesi sihloko uqukethe izinhlangano ezimbili: Umuntu noMasipala. Ubuhlobo obulodwa bokuthi "Ukuphila" bubopha lezi zinto ndawonye. Umuntu ngamunye uhlala edolobheni elilodwa kuphela, kodwa idolobha ngalinye lingakhonza abantu abaningi. Esikhathini somdwebo, izimfanelo ziyigama lomuntu nomphakathi womuzi. Ngokuvamile, amagama okusetshenziswa asetshenziselwa ukuchaza izinto nezinhlamvu, kuyilapho izenzo zisetshenziselwa ukuchaza ubuhlobo.
Izinhlangano
Into ngayinye oyilandelayo ku-database iyinhlangano, futhi inhlangano ngayinye iyithebula kudatha lokuxhumana. Ngokuvamile, into ngayinye ku-database ihambisana nomugqa. Uma une database equkethe amagama abantu, inhlangano yayo kungase kuthiwa "Umuntu." Itafula elinamagama afanayo lalizobe likhona ku-database, futhi wonke umuntu uzobekwa kuloluhlu etafuleni lomuntu.
Izimfanelo
Ulwazi oluqukethe ulwazi mayelana nenhlangano ngayinye. Lolu lwazi lubizwa ngokuthi "izimfanelo." futhi liqukethe imininingwane eyingqayizivele ngayinye ebhalwe ohlwini. Esibonelweni somuntu, izimfanelo zingabandakanya igama lokuqala, igama lokugcina, inombolo yokuzalwa kanye nenombolo yokukhomba. Izimfanelo zinikeza ulwazi oluningiliziwe mayelana ne-entity. Esikhathini sedatha yokuxhumana, izimfanelo zigcinwa emasimini lapho imininingwane egcinwe khona irekhodi. Awunqunyelwe kunani elithile lezimfanelo.
Ubudlelwane
Inani le-diagram-ubudlelwane lobuhlobo lisekhono layo lokubonisa ulwazi mayelana nobuhlobo phakathi kwezinhlangano. Esikhathini sethu, ungakwazi ukulandelela ulwazi mayelana nomuzi lapho umuntu ngamunye ehlala khona. Ungaphinde ulandele ulwazi mayelana nomuzi ngokwawo enkampanini yomuzi ngobuhlobo obubopha ndawonye Ulwazi lwabantu nolwazi lomuzi.
Indlela Yakha I-ER Diagram
- Dala ibhokisi ngenhlangano ngayinye noma umqondo ofanelekayo kumodeli wakho.
- Dweba imigqa ukuze uxhume izinhlangano ezihlobene ukuze ufanise ubuhlobo. Bhala ubuhlobo usebenzisa izenzi ngaphakathi kwamehlo edayimane.
- Thola izici ezifanele zenkampani ngayinye, kuqala ngezici ezibaluleke kakhulu, futhi uzifake ku-ovals kumdwebo. Kamuva, ungenza uhlu lwakho lwezinhlamvu luvezwe ngokuningiliziwe.
Uma usuqedile, uzobe ucacise ngokucacile ukuthi imibono yebhizinisi ehlukile ihlobene kanjani, futhi uzoba nesisekelo somqondo wokwakheka kwedatha yokuxhumana ekusekeleni ibhizinisi lakho.