Akwa bụ àgwà nwere ike iji chọpụta ihe ndekọ data
Akwa bụ ma otu ma ọ bụ njikọta àgwà ndị nwere ike iji mee ka ị mata ihe ndekọ data nchekwa data. Okpokoro nwere ike ịnwe ọtụtụ mkpakọ nke na-emepụta superkeys.
Nlereanya Superkey
Tebụl na ubi
Aha | Afọ | SSN | Ekwentị Ext. |
---|---|---|---|
Robert Jones | 43 | 123-45-6789 | 123 |
Bet Smith | 43 | 234-56-7890 | 456 |
Robert Jones | 18 | 345-67-8901 | 789 |
Dị ka ị nwere ike ịhụ, ogidi nke
Ụdị Superkeys
N'ime ndị edepụtara n'elu tebụl n'elu, nanị
A na-akpọkwa Ọ bụrụ na tebụl enweghị ihe A ga-akpọ nọmba ndị ọrụ ọhụrụ ahụ isi nchịkọta isi. Igodo isi ihe a ga-abụkwa onyeisi.