Dzivisa Kuchinja Kwokutenderera Kubatsira Kuchengetedza Normalization
Kushandura kwechinyorwa mu database kune hukama husina kukanganisa huri pakati petafura imwechete iyo inokonzera kushanda kunoshanda . Kuti uite zvinowanzoenderana nehutatu hweFomu yeHanormal Form (3NF), unofanira kubvisa chero kushanduka kwekutendeuka.
Nenzira yaro, kutarisa kwekutendeuka kunodikanwa zvitatu kana kupfuura zvinowanikwa (kana zvinyorwa zvemasvomhu) zvine basa rinoenderana pakati pavo, zvinoreva kuti Rudzi rwekutanga A riri patafura rinotenderera paChitamu B kuburikidza neChitamu C.
Ngationei kuti izvi zvingashanda sei.
Transitive Dependency Example
VANHU
| Author_ID | Munyori | Bhuku | Author_Nationality |
|---|---|---|---|
| Auth_001 | Orson Scott Card | Ender's Game | nyika dzakabatana |
| Auth_001 | Orson Scott Card | Ender's Game | nyika dzakabatana |
| Auth_002 | Margaret Atwood | The Handmaid's Tale | Kanadha |
Mumuenzaniso weAUTHORS pamusoro apa:
- Bhuku → Munyori : Pano, chirevo cheBhuku chinogadzirisa chirevo cheMunyori . Kana iwe uchiziva zita rebhuku, unogona kudzidza zita romunyori. Zvisinei, Munyori haatauri Bhuku , nokuti munyori anogona kunyora mabhuku akawanda. Somuenzaniso, nokuti tinoziva zita romunyori weOrson Scott Card, isu hatichizivi zita rebhuku.
- Munyori → MutevedzeriMunyika yose : Saizvozvowo, chirevo cheMunyori chinogadza Munyori_Nyika , asi kwete imwe nzira yakapoteredza; nekuda kwekuti tinoziva kuti nyika haina kureva kuti isu tinokwanisa kugadzirisa munyori.
Asi tafura iyi inotanga kutenderera kwekutendeuka:
- Bhuku → Munyori_Nationality: Kana tichiziva zita rebhuku, tinogona kuona hutungamiri kuburikidza neChinyorwa chinyorwa.
Kudzivisa Kuchinja Kutendeseka
Kuti tive nechokwadi cheTatu yeHome Form, ngatibvisei kutenderera kwekutendeuka.
Tinogona kutanga nokubvisa korona yeBhuku kubva patafura yeVanyori nekugadzira tafura yemabhuku yakasiyana:
BHUKU
| Book_ID | Bhuku | Author_ID |
|---|---|---|
| Book_001 | Ender's Game | Auth_001 |
| Book_001 | Vana veMafungiro | Auth_001 |
| Book_002 | The Handmaid's Tale | Auth_002 |
VANHU
| Author_ID | Munyori | Author_Nationality |
|---|---|---|
| Auth_001 | Orson Scott Card | nyika dzakabatana |
| Auth_002 | Margaret Atwood | Kanadha |
Izvi zvakagadzirisa here? Ngationgororei kuvimba kwedu zvino:
BHUKU DHA :
- Book_ID → Bhuku: Bhuku rinoenderana neBhuku_ID .
- Hapana humwe hutariro huri mutafura ino huripo, saka tiri vakanaka. Cherechedza kuti kiyi yekunze Author_ID inoshanyira tafura iyi patafura yaAUTHORS kuburikidza nechigamba chayo chikuru Author_ID . Takasika ukama kuti tisave kutenderera kwekutendeuka, chinhu chinokosha chekodzero dzehukama.
Tafura yevanyori :
- Munyori_ID → Munyori: Munyori anobva paMunyori_ID .
- Munyori → MutevedzeriMunyika: Rudzi rwenyika runogona kugadziriswa nemunyori.
- Mutevedzeri_ID → MutevedzeriNyika: Unhu hunogona kutarirwa kubva kuMunyori_ID kuburikidza neChiratidzo cheMunyori . Tichiri kuva nekutenderera kushanduka.
Tinofanira kuwedzera tafura yechitatu kuti tifunge iyi data:
NYIKA
| Country_ID | Nyika |
|---|---|
| Coun_001 | nyika dzakabatana |
| Coun_002 | Kanadha |
VANHU
| Author_ID | Munyori | Country_ID |
|---|---|---|
| Auth_001 | Orson Scott Card | Coun_001 |
| Auth_002 | Margaret Atwood | Coun_002 |
Iye zvino tava nematafura matatu, tichishandisa zvigere zvekunze zvekubatanidza pakati pematafura:
- Bhuku reKOKUDZISA mutambo wekune dzimwe nyika Munyori_ID inobatanidza bhuku kune munyori mune tafura yeAUTHORS.
- Iko mutsetse wepagore reAUTHORS wekune imwe nyika Country_ID inosangana munyori kunyika kune COUNTRIES tafura.
- Itafura yeCOUNTRA haina kiyi yekunze nokuti haifaniri kudirana kune imwe tafura mune iyi yakagadzirwa.
Nei Kutenderera Kwezvokutendeseka Kwakashata Mashoko Akasikwa
Ndeipi kukosha kwekudzivirira kutenderera kwekutendeuka kubatsira kubatsira 3NF? Ngatimbokurukura tafura yedu yekutanga zvakare uye tione nyaya inogadzira:
VANHU
| Author_ID | Munyori | Bhuku | Author_Nationality |
|---|---|---|---|
| Auth_001 | Orson Scott Card | Ender's Game | nyika dzakabatana |
| Auth_001 | Orson Scott Card | Vana veMafungiro | nyika dzakabatana |
| Auth_002 | Margaret Atwood | The Handmaid's Tale | Kanadha |
Rudzi urwu rwekugadzira runogona kuita kuti deta dzisiyane uye dzisingabvumirane, semuenzaniso:
- Kana iwe ukabvisa mabhuku maviri e "Vana veMafungiro" uye "Ender's Game," iwe unogona kubvisa munyori "Orson Scott Card" uye hukama hwake zvakakwana kubva kune database.
- Iwe haugoni kuwedzera munyori mutsva kune database kunze kwekuti iwe uwedzerewo bhuku; zvakadini kana munyori asati adhindwa kana iwe usingazivi zita rebhuku raakanyora?
- Kana "Orson Scott Card" yakashandura ukama hwake, iwe unofanirwa kuishandura muzvinyorwa zvose zvaanoonekwa. Kuva nezvinyorwa zvakasiyana-siyana nemunyori mumwechete zvinogona kuguma nemashoko asina kururama: zvakadini kana munhu wekupinda data asingacherecheri pane dzakawanda zvinyorwa kwaari uye anoshandura dhidhi mune imwe chete rekodhi?
- Iwe haugoni kubvisa bhuku rakafanana ne "The Handmaid's Tale" pasina kubvisa munyori zvachose.
Izvi zvinongova zvimwe zvikonzero nei kuisa tsika , nekudzivirira kuzvidzora kwekutendeuka, kuchengetedza deta uye kuvimbisa kusagadzikana.