Ka guji Tsarin Dama na Tsarin Don Taimaka Tabbatar Faɗakarwa
Tsarin dogara a cikin bayanai shine dangantaka ta kai tsaye tsakanin dabi'u a cikin teburin guda wanda ke haifar da dogara ga aikin . Don cimma daidaitattun ka'ida na Uku na Uku (3NF), dole ne ka kawar da duk wani abin da ya dace.
Ta wurin yanayinsa, dogarawa na gaba yana buƙatar alamomi uku ko fiye (ko ginshiƙan bayanai) waɗanda ke da tasiri na aiki tsakanin su, ma'ana cewa Column A a cikin tebur yana dogara akan Shafin B ta hanyar Tsarin C.
Bari mu ga yadda wannan zai iya aiki.
Hanyar Ɗaukaka Tsarin Gyara
AUTHORS
Author_ID | Mawallafin | Littafin | Author_Nationality |
---|---|---|---|
Auth_001 | Orson Scott Card | Ender's Game | Amurka |
Auth_001 | Orson Scott Card | Ender's Game | Amurka |
Auth_002 | Margaret Atwood | Handmaid's Tale | Canada |
A cikin misalin AUTHORS a sama:
- Littafin → Mawallafi : A nan, Sakamakon littafi yana ƙayyade mawallafi . Idan kun san sunan littafin, za ku iya koyan sunan marubucin. Duk da haka, Mawallafin bai ƙayyade Littafin ba , saboda marubucin zai iya rubuta littattafai masu yawa. Alal misali, kawai saboda mun san sunan marubucin sunan Orson Scott Card, har yanzu ba mu san sunan littafin ba.
- Mawallafi → Mawallafi : Hakazalika, Mawallafa mai siffanta yana ƙayyade mawallafin , amma ba hanyar da ke ciki ba; kawai saboda mun san dan kasa ba yana nufin za mu iya sanin marubucin.
Amma wannan tebur yana gabatar da daidaituwa:
- Littafin → Mawallafi: Idan mun san sunan littafi, za mu iya ƙayyade ta asali ta hanyar Mawallafin rubutun.
Guje wa Tsarin Dama
Don tabbatar da takardun al'ada na uku, bari mu cire maƙalarin haɗakarwa.
Za mu iya farawa ta cire rubutun Littafin daga teburin Tushen da kuma samar da takardun Littattafai daban-daban:
LITTAFI
Book_ID | Littafin | Author_ID |
---|---|---|
Book_001 | Ender's Game | Auth_001 |
Book_001 | Yara na Mind | Auth_001 |
Book_002 | Handmaid's Tale | Auth_002 |
AUTHORS
Author_ID | Mawallafin | Author_Nationality |
---|---|---|
Auth_001 | Orson Scott Card | Amurka |
Auth_002 | Margaret Atwood | Canada |
Shin wannan ya gyara shi? Bari mu bincika masu dogara a yanzu:
LITTAFI tebur :
- Book_ID → Littafin: Littafin ya dogara ne akan Book_ID .
- Babu sauran ƙididdiga a wannan tebur akwai, don haka muna lafiya. Ka lura cewa maƙallacin asali mai mahimmanci Author_ID ya danganta wannan tebur zuwa tebur AUTHORS ta hanyar maɓallin farko na Author_ID . Mun kirkiro dangantaka don kauce wa mutunci, wanda ke da mahimmanci na zane-zane.
La'akari na AUTHORS :
- Author_ID → Author: Author ya dogara da Author_ID .
- Mawallafi → MawallafaTawalin: Ƙwararren za ta iya ƙaddamar da kasa.
- Author_ID → Author_Nationality: Ƙasar za a iya ƙaddara daga Author_ID ta hanyar Mawallafi mai sifa. Har yanzu muna da mutuntaka.
Muna buƙatar ƙara tayi na uku don daidaita wannan bayanan:
COUNTRIES
Country_ID | Ƙasar |
---|---|
Coun_001 | Amurka |
Coun_002 | Canada |
AUTHORS
Author_ID | Mawallafin | Country_ID |
---|---|---|
Auth_001 | Orson Scott Card | Coun_001 |
Auth_002 | Margaret Atwood | Coun_002 |
Yanzu muna da tebur uku, yin amfani da maɓalli na waje don haɗi tsakanin Tables:
- Rubutun asusun waje na BOOK na Author_ID ya danganta littafi ga marubucin a cikin tebur AUTHORS.
- Ƙungiyar kasashen waje ta AUTHORS Country_ID ta danganta marubucin zuwa wata ƙasa a cikin tebur COUNTRIES.
- Tebur na kasa ba shi da maƙasudin waje don ba shi da bukatar haɗi zuwa wani tebur a wannan zane.
Me yasa Dandalin Tsayawa Tsuntsauran Kasa Dama Cikin Gida
Mene ne darajar kauce wa ƙididdigar haɗari don taimakawa wajen tabbatar da 3NF? Bari mu sake duba maɓallinmu na farko kuma mu ga batutuwan da ta haifar:
AUTHORS
Author_ID | Mawallafin | Littafin | Author_Nationality |
---|---|---|---|
Auth_001 | Orson Scott Card | Ender's Game | Amurka |
Auth_001 | Orson Scott Card | Yara na Mind | Amurka |
Auth_002 | Margaret Atwood | Handmaid's Tale | Canada |
Irin wannan nau'i na iya taimakawa ga abubuwan da ke faruwa da kuma rashin daidaitattun bayanai, misali:
- Idan ka share littattafai guda biyu "Yara na Mind" da kuma "Ender's Game," za ka share marubucin "Orson Scott Card" da kuma dan kasa gaba ɗaya daga bayanan.
- Ba za ku iya ƙara sabon marubucin zuwa ga bayanai ba sai dai idan kuna ƙara littafi; idan har marubucin bai riga ya buga ba ko ba ku san sunan littafin da ta rubuta ba?
- Idan "Orson Scott Card" ya canza matsayin ɗan ƙasa, dole ne a canza shi a cikin dukan bayanan da ya bayyana. Samun rubutun da yawa tare da wannan marubucin zai iya haifar da bayanan da ba daidai ba: idan mutum mai shigar da bayanai ba ya gane cewa akwai rubutun da yawa a gare shi kuma ya canza bayanan a cikin guda ɗaya rikodin?
- Ba za ku iya share littafin kamar "The Handmaid's Tale" ba tare da kawar da marubucin gaba ɗaya ba.
Wadannan sune wasu dalilan da ya sa ke daidaitawa , da kuma guje wa ƙididdigar haɗari, kare bayanai da tabbatar da daidaito.