Zere Omume Na-agafe Na-enyere Gị aka Ijide n'aka na Ịhazi
Ntụkwasị obi na-adabere na nchekwa data bụ njikọ na-enweghị isi n'etiti ụkpụrụ dị n'otu tebụl nke na-eme ka ịdabere na arụ ọrụ . Iji mezuo ụkpụrụ normalization nke Ụdị Ntọala nke Atọ (3NF), ị ghaghị ịkwụsị ntụkwasị obi ọ bụla.
Site na ọdịdị ya, njide ntụkwasị obi na-achọ ihe atọ ma ọ bụ karịa (ma ọ bụ ogidi nchekwa data) nke nwere arụ ọrụ na-adabere n'etiti ha, nke pụtara na kọlụm A na tebụl dabere na Mkpụrụ akwụkwọ B site na Kọmitii nkeji C.
Ka anyị lee otú nke a nwere ike isi rụọ ọrụ.
Ihe Nlereanya Na-eme Ka Mmadụ Nwee Ike
NDỊ aka
Author_ID | Onye edemede | Akwụkwọ | Onye na-edebanye aha ya |
---|---|---|---|
Auth_001 | Orson Scott Card | Ender Egwuregwu | United States |
Auth_001 | Orson Scott Card | Ender Egwuregwu | United States |
Auth_002 | Margaret Atwood | The Handmaid's Tale | Canada |
N'okpuru AUTHORS n'elu:
- Akwụkwọ → Chepụtara : N'ebe a, njirimara nke Akwụkwọ na-ekpebi Onye chepụtara . Ọ bụrụ na ị maara akwụkwọ aha, ị nwere ike ịmụta aha onye edemede ahụ. Otú ọ dị, Onye edemede anaghị ekpebi Akwụkwọ , n'ihi na onye edemede nwere ike ide akwụkwọ dị iche iche. Dịka ọmụmaatụ, naanị n'ihi na anyị maara aha onye edemede ahụ bụ Orson Scott Card, anyị ka na-amaghị akwụkwọ aha ahụ.
- Onye edemede → Author_Nationality : N'otu aka ahụ, Onye chepụtara ihe na-ekpebi Onye chepụtara , ma ọ bụghị ụzọ ọzọ; naanị n'ihi na anyị maara na mba a apụtaghị na anyị nwere ike ikpebi onye edemede.
Ma okpokoro a na-ewebata ntụkwasị obi na-agbanwe agbanwe:
- Book → Author_Nationality: Ọ bụrụ na anyị maara akwụkwọ aha ahụ, anyị nwere ike ikpebi mba site na kọlụm edemede.
Izere Dependencies Dependencies
Iji hụ akwụkwọ atọ nke atọ, ka anyị wepụ ihe ndabere ahụ.
Anyị nwere ike ịmalite site na iwepụ kọlụm kọlụm site na teepu ndị Authors na ịmepụta akwụkwọ dị iche iche:
AKWỤKWỌ
Book_ID | Akwụkwọ | Author_ID |
---|---|---|
Book_001 | Ender Egwuregwu | Auth_001 |
Book_001 | Ụmụ nke Mind | Auth_001 |
Book_002 | The Handmaid's Tale | Auth_002 |
NDỊ aka
Author_ID | Onye edemede | Onye na-edebanye aha ya |
---|---|---|
Auth_001 | Orson Scott Card | United States |
Auth_002 | Margaret Atwood | Canada |
Ndi emi ama anam enye? Ka anyị nyochaa ntụkwasị obi anyị ugbu a:
Isiokwu Akwụkwọ :
- Book_ID → Akwụkwọ: Akwụkwọ dabeere na Book_ID .
- Enweghị ntụrụndụ ndị ọzọ na tebụl a dị, ya mere anyị dị mma. Rịba ama na isi mba ọzọ bụ Author_ID tinyere okpokoro a na tebụl AUTHOR site na isi edemede ya bụ Author_ID . Anyị emeela mmekọrịta iji zere ịdabere na-agbanwe agbanwe, ihe ntinye dị mkpa nke ọdụ data njikọta.
OWU NDỊ AUTHOR :
- Author_ID → Author: Onye chepụtara na- adabere na Author_ID .
- Onye edemede → Chepụtara onwe onye n'aka: Onye nwe akwukwo nwere ike kpebisiri ike.
- Author_ID → Book_Nationality: A pụrụ ikpebi mba site n'aka Author_ID site n'aka onye chepụtara . Anyị ka na-atụgharị uche.
Anyị kwesịrị itinye okpukpu atọ iji normalize data a:
Mba
Country_ID | Mba |
---|---|
Coun_001 | United States |
Coun_002 | Canada |
NDỊ aka
Author_ID | Onye edemede | Country_ID |
---|---|---|
Auth_001 | Orson Scott Card | Coun_001 |
Auth_002 | Margaret Atwood | Coun_002 |
Ugbu a, anyị nwere tebụl atọ, na - eji igodo ndị ọzọ ejikọta n'etiti tebụl:
- Akwụkwọ edemede isi akwụkwọ nke BOOK Author_ID na- ejikọta otu akwụkwọ na onye edemede nọ na tebụl AUTHOR.
- Ulo ala di iche iche nke AUTHORS Country_ID jikọtara onye na-ede akwụkwọ na mba dị na tebụl mba.
- Ntanye mba enweghị isi mba ọzọ n'ihi na ọ dịghị mkpa ijikọta na tebụl ọzọ na nke a.
Ihe mere na ndi mmadu bu ndi na-eme ihe na-adighi adighi nma
Kedu uru ị na-ezere iji tụgharịa uche iji mee ka ị hụ 3NF? Ka anyị tụlee okpokoro mbụ anyị ma hụ nsogbu ọ na - eme:
NDỊ aka
Author_ID | Onye edemede | Akwụkwọ | Onye na-edebanye aha ya |
---|---|---|---|
Auth_001 | Orson Scott Card | Ender Egwuregwu | United States |
Auth_001 | Orson Scott Card | Ụmụ nke Mind | United States |
Auth_002 | Margaret Atwood | The Handmaid's Tale | Canada |
Ụdị ụdị a nwere ike itinye aka na nchịkọta data na nkwekọrịta, dịka ọmụmaatụ:
- Ọ bụrụ na ị ehichapụrụ akwụkwọ abụọ "Ụmụaka Mind" na "Ender's Game," ị ga-ehichapụ onye dere "Orson Scott Card" na mba ya kpamkpam site na nchekwa data ahụ.
- I nweghị ike itinye onye edemede ọhụrụ na nchekwa data ma ọ bụrụ na ị gbakwunye akwụkwọ; kedu ihe ma ọ bụrụ na ederedebeghị akwụkwọ ma ọ bụ na ị maghị aha akwụkwọ ọ dere?
- Ọ bụrụ na "Orson Scott Card" gbanwere ụmụ amaala ya, ị ga-agbanwe ya na ndekọ ọ bụla ọ pụtara. Inwe otutu ederede na otu onye edemede a nwere ike iduzi data ezighi ezi: ihe ma ọ bụrụ na onye ntinye data adighi amata na otutu edere ya ma weghachite data na otu ihe ndekọ?
- I nweghị ike ihichapụ akwụkwọ dị ka "The Handmaid's Tale" na-enweghịkwa ihichapụ onye edemede ahụ kpamkpam.
Ndị a bụ naanị ụfọdụ ihe kpatara normalization , ma zere ịdabere na nsụgharị, chebe data ma hụ na agbanwe agbanwe.