Kedu ihe bụ Transitive Dependency na nchekwa data

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:

Ma okpokoro a na-ewebata ntụkwasị obi na-agbanwe agbanwe:

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 :

OWU NDỊ AUTHOR :

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:

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:

Ndị a bụ naanị ụfọdụ ihe kpatara normalization , ma zere ịdabere na nsụgharị, chebe data ma hụ na agbanwe agbanwe.