Makullin mahimman bayanai shine hanya mafi sauki don ƙirƙirar haɗin kai mai dacewa
Kamar yadda ka rigaya sani, bayanan bayanai suna amfani da launi don tsara bayanai. (Idan ba ka da masaniya da basirar bayanai, karanta Abin da ke Database? ) Kowace tebur yana kunshe da yawan layuka, kowannensu ya dace da rikodin bayanai guda ɗaya. Don haka, ta yaya bayanai zasu kiyaye dukkan waɗannan rubutun? Yana da ta hanyar amfani da makullin.
Ƙaramar Farawa
Na farko nau'in maɓallin da za mu tattauna shi ne maɓallin farko . Kowane ɗakin labarun ya kamata a sami ɗaya ko fiye da ginshiƙai da aka zaɓa a matsayin maɓallin farko . Darajar wannan maɓallin kewayawa ya zama na musamman ga kowane rikodin a cikin bayanai.
Alal misali, ɗauka muna da tebur da ake kira ma'aikata wanda ya ƙunshi bayanin ma'aikata ga kowane ma'aikacin kamfaninmu. Muna so mu zaɓi maɓallin farko mai dacewa wanda zai gane kowacce ma'aikaci. Da farko tunaninku na iya zama don amfani da sunan ma'aikacin. Wannan ba zai yi aiki sosai ba saboda yana tunanin cewa za ku yi aiki da ma'aikata biyu tare da wannan suna. Kyakkyawar zabi zai iya amfani da lambar ID na ma'aikaci na musamman da ka sanya wa kowane ma'aikacin lokacin da suke hayar. Wasu kungiyoyi suna son yin amfani da Lissafin Tsaro na Yanayi (ko masu kama da gwamnati) don wannan aiki saboda kowane ma'aikaci yana da ɗaya kuma suna tabbas su zama na musamman. Duk da haka, yin amfani da Lissafin Tsaron Lafiya don wannan dalili yana da matukar damuwa saboda damuwa na sirri. (Idan kuna aiki don kungiya ta gwamnati, yin amfani da lambar Tsaron Tsaro na iya zama doka a karkashin Dokar Tsare Sirri ta 1974.) Saboda haka, yawancin kungiyoyi sun canza zuwa amfani da masu ganowa na musamman (ID na ma'aikaci, ID na dalibai, da dai sauransu). .) wanda ba ya raba wadannan damuwa na sirri.
Da zarar ka yanke shawara a kan maɓalli na farko da kuma kafa ɗakunan bayanai, tsarin kula da bayanai zai tabbatar da bambancin da ke cikin maɓallin.
Idan kayi kokarin sanya rikodin a cikin tebur tare da maɓallin farko wanda ya yi rikodin rikodin rikodin, toshe zai kasa.
Yawancin bayanan bayanai suna iya samar da maɓallin maɓallin kansu. Microsoft Access, alal misali, za a iya saita su don amfani da irin bayanai na AutoNumber don sanya wani ID na musamman a kowane rikodin a cikin tebur. Duk da yake yana da tasiri, wannan mummunan zane ne saboda ya bar ku da ma'ana maras muhimmanci a kowace rikodin a teburin. Me yasa ba amfani da wannan wuri don adana wani abu mai amfani ba?
Ƙasashen waje
Wani nau'in shine maɓallin waje , wanda aka yi amfani da ita don ƙirƙirar dangantaka tsakanin tebur. Abinda ke da dangantaka a tsakanin Tables a mafi yawan tsari. Komawa zuwa Database database, yi tunanin cewa muna so mu ƙara tebur da ke ƙunshe da bayanan ma'aikatar bayanai. Za'a iya kiran wannan saiti na Ƙungiyoyin kuma zai ƙunshi babban adadin bayanai game da sashen a matsayin cikakke. Muna so mu hada da bayanai game da ma'aikata a cikin sashen, amma zai zama ba tare da dalili ba don samun wannan bayani a cikin tebur biyu (ma'aikata da kuma ma'aikatun). Maimakon haka, zamu iya ƙirƙiri dangantaka tsakanin teburin biyu.
Bari mu ɗauka cewa tebur na Departments yana amfani da shafi na Ma'aikatar ta matsayin maɓallin farko. Don ƙirƙirar dangantaka tsakanin teburin guda biyu, za mu ƙara sabon shafi zuwa teburin ma'aikata da ake kira Sashen. Sai muka cika sunan sashen wanda kowane ma'aikaci yake. Har ila yau, muna sanar da tsarin gudanar da bayanai da cewa sashen Sashen a cikin tebur ma'aikata shi ne maɓallin waje wanda ke nuna alamun Tables.
Bayanan ɗin za su tilasta tabbatar da mutuntaka ta hanyar tabbatar da cewa dukkanin dabi'un da ke cikin sassan Tashoshi na ma'aikatan ma'aikata suna da takaddun shigarwa a cikin tebur na Departments.
Yi la'akari da cewa babu bambanci da aka bambanta don maɓallin waje. Ƙila mu (kuma mafi mahimmanci) suna da ma'aikata fiye da ɗaya wanda ke cikin sashen guda ɗaya. Hakazalika, babu wani dalili da cewa shigarwa a cikin tebur na Departments yana da shiga shiga cikin ma'aikatan ma'aikata. Zai yiwu muna son samun sashen ba tare da ma'aikata ba.
Don ƙarin bayani a kan wannan batu, karanta Ƙirƙirar Ƙananan Keɓance .