Kurongedza Database yako
Kana iwe wakanga uchishanda nedatabases kwekanguva, mikana iwe wakanzwa izwi rechimiro. Zvichida mumwe munhu akakubvunza iwe kuti "Ndizvo zvinyorwa zvinowanikwa here?" kana kuti "Ndizvo here muBBCNF ?" Normalization inowanzoputirwa kunze semafambisirwo ekuti vadzidzisi chete vane nguva ye. Zvisinei, kuziva mitemo yekusimudzira uye kuishandisa kune rimwe dhivhesiti yako yezuva nezuva yakagadzirirwa mabasa chaizvoizvo haisi yose yakaoma uye inogona kuwedzera zvakanyanya kushanda kweDBMS yako.
Muchikamu chino, tichaisa pfungwa yekusimudzira uye tifunge kwenguva pfupi maitiro akajairika.
Chii Chinonzi Normalization?
Normalization ndiyo nzira yekugadzira zvakanakisisa data mune database. Pane zvinangwa zviviri zvekugadzirisa zvinhu: kubvisa dambudziko rekudzivirirwa (somuenzaniso, kuchengetedza dheyedhi yakafanana mune imwe yefurafura imwechete) uye kuvimbisa kuchengetedzeka kwezvinhu zvichiita pfungwa (kungochengetedza data yakabatana iri patafura). Zvose izvi zvinangwa zvakakodzera sezvavanoderedza kuwanda kwenzvimbo iyo database inoshandisa uye inochengetedza kuti data inogadziriswa.
Maitiro Anowanikwa
Dunhu re database rakagadzira mutsara wemitemo yekuvimbisa kuti zvinyorwa zvemashoko zvakasikwa. Izvi zvinonzi maitiro ezvisikwa uye zvinoverengwa kubva kune imwe (iyo yakaderera kupfuura yese yekusimudzira, inozivikanwa sewomufambiro wekutanga kana 1NF) kuburikidza nechishanu (yechishanu fomu yakakwana kana 5NF). Mune maitiro anobatsira, iwe unowanzoona 1NF, 2NF, uye 3NF pamwe chete ne4NF dzimwe nguva. Chechipiri chimiro chechimiro chinonyanya kuonekwa uye hachizogadzirwi munyaya ino.
Tisati tatanga hurukuro yedu pamusoro pemafomu akasiyana-siyana, zvakakosha kuratidza kuti inongova mitemo uye mirayiridzo chete. Dzimwe nguva, zvinova zvakafanira kupotsa kubva kwavari kuti vawane zvinoshanda zvebhizimisi zvinodiwa. Zvisinei, kana kuchinja kuitika, zvakakosha zvikuru kuongorora chero zvingangodaro zvavanogona kuita pane yako system uye nenyaya yezvinobvumirana. Izvozvo zvakati, ngatitsvakei maitiro akajairika.
Fomu Yokutanga Yakasikwa (1NF)
Chokutanga chimiro chemazuva ose (1NF) chinogadzirisa mitemo inokosha ye database yakarongeka:
- Bvisa zvinyorwa zvinyorwa kubva patafura rimwe chete.
- Gadzira mahwendefa akaparadzana eboka rimwe nerimwe re data rakabatana uye ona mutsara wega wega nekeri yakasiyana-siyana kana seti yemakoroni ( inokosha yekutanga ).
Fomu Yechipiri Yakasarudzika (2NF)
Chechipiri chimiro chechimiro (2NF) chinotarisa zvakare pfungwa yekubvisa dplicative data :
- Garai zvose zvinodiwa zvekutanga maitiro.
- Bvisa zvinyorwa zvemashoko zvinoshanda kumitsara yakawanda yefurafura uye uzviise mumatafura akasiyana.
- Ita hukama pakati pematafura aya matsva uye avo vanofanotanga kuburikidza nokushandiswa kwezvikwere zvekunze .
Yechipiri Yomufomu Form (3NF)
Chechitatu chimiro chechimiro (3NF) chinoenda kune imwe danho guru rinowedzera:
- Garai zvose zvinodiwa zvechipiri chimiro chechimiro.
- Bvisa zvinyorwa zvisingatenderi pachikona chikuru.
Boyce-Codd Normal Form (BCNF kana 3.5NF)
Iyo Boyce-Codd Fomu Yakarongeka, iyo inonziwo "yechitatu nehafu (3.5) fomu yakasarudzika", inowedzera imwezve inodikanwa:
- Ita zvose zvinodiwa zvechitatu chemafomu chaiwo.
- Chimwe nechimwe chinogadzirisa chinofanira kunge chiri chinhu chakakosha.
Nhamba Yechichina Yechina (4NF)
Pakupedzisira, chechina chechina chimiro (4NF) chine chimwe chinhu chinodiwa:
- Ita zvose zvinodiwa zvechitatu chemafomu chaiwo.
- Ukama huri muna 4NF kana husina hutsika hwakawanda hunotarisirwa .
Yeuka, izvi zvinowirirana mazano zvinowedzera. Kuti iine database inenge iri muN2NF, inofanira kutanga inzadzisa zvose zvinotarisirwa nhepfenyuro yeNNF.
Ndinofanira Kuita Zvose Here?
Kunyange zvazvo kugadziriswa kwemasvomhu kune dzimwe nguva pfungwa yakanaka, haisi mhedziso yakakwana. Muzvokwadi, kune dzimwe mamiriro ekuputsa nemaune mitemo yekusimudzira tsika yakanaka. Nokuda kweizvi pamusoro pechinyorwa chino, verenga Ndinofanira Kugadzirisa Nhamba Yangu Yakachengetedzwa?
Kana iwe uchida kuongorora kuti database yako yakasikwa, tanga nekudzidza kuti iwe ungaisa sei dhesi yako muChechi Yechipatara .