Zvikanganiso Zvakajairika Zvakaitwa muDhindedzwa Dhizivo

Pasinei nokuti uri kushanda ne database yakachengeta mazana erekodhi kana mamiriyoni emarekodhi, zvakakodzera kugadzirwa kwepa database zvinogara zvichikosha. Hakusi kungoita kuti kuwana mashoko acho nyore nyore, kuchaitawo kuti zvigadzirise kuwedzera dhesiyo munguva yemberi. Zvinosuruvarisa, zviri nyore kupinda mumasungo mashomanana anogona kuita kuti zvinhu zviome munguva yemberi.

Iko kune mabhuku ose akanyorwa pamusoro penyaya ye normalis a database, asi kana ukangodzivisa zvikanganiso izvi zvinowanzoitika, iwe uchava nenzira yakarurama kune yakanaka yekugadzirisa dhina.

Database Mistake # 1: Kudzokorora Minda Mumatafura

Murairo wekutanga wechigunzva chekodhidhi yakagadziriswa ndeyekubvuma kudzokorora deta uye kuisa mazamu aya anodzokorora ari patafura yavo. Kudzokorora minda iri patafura kunowanzoonekwa kune avo vakabva kunyika yepaspereti, asi apo maspredishiti anowanzove akareruka nekugadzirwa, databases inofanira kunge yakabatana. Zvakafanana nokuenda kubva 2D kusvika ku 3D.

Nenguva isipi, kudzokorora minda inowanzova nyore kuona. Ingotarisa patafura iyi:

Chii chinoitika kana urongwa huine zvinhu zvina? Tichada kuwedzera imwe munda kune tafura kuti titsigire zvinhu zvinopfuura zvitatu. Uye kana takavaka mushandisi wekombiyuta kumativi etafura kuti tibatsire dhiyabhorosi yenyaya, tinogona kuigadzirisa neyo mitsva yemiti. Uye isu tinowana sei mirairo yose neJellybeans muhurongwa? Tichadzvinyirirwa kuti tibvunze mhando yese yemiti yemuchina mutafura neshoko reSQL rinogona kutaridzika se: SELECT * KUBVA MICHIKA ZVAKAI Product1 = 'Jelly Beans' OR Product2 = 'Jelly Beans' OR Product3 = 'Jelly Beans'.

Panzvimbo pokuva nefurafura imwechete iyo inokonzera ruzivo rwuri pamwe chete, tinofanira kuva nematafura matatu kuti rimwe nerimwe rive nechikamu chakasiyana chemashoko. Mumuenzaniso uyu, tinoda kuti Mutemo upiwe nehuwandu hwehutori iwoyo, Mishonga yefurafura nezvose zvezvigadzirwa zvedu uye tablet ye ProductOrders iyo yakabatanidza zvigadzirwa nemutemo.

Cherechedza kuti tafura imwe neimwe ine nhengo yake yakasiyana sei yeAIDS. Ichi ndicho chinonyanya kukosha. Tinobatanidza tafura tichishandisa chinhu chikuru chekukosha sekiyi yekunze mune imwe tafura. Verenga zvakawanda pamusoro peiyi makii nekunze kwekiki.

Dhiyabhorosi Mistake # 2: Kubudisa Dhafura muTebhenekeri

Ichi ndicho chimwe chikanganiso chakakurumbira, asi haisi nguva dzose kumira zvakanyanya sekudzoka kweminda. Paunenge uchinyora database, unoda kuve nechokwadi kuti data yose iri patafura inoenderana neyoyoga. Zvakafanana nemutambo wemwana iwoyo pamusoro pekuona izvo zvakasiyana. Kana iwe une bhanana, sitirobheri, peach uye terevhizheni, terevhizheni inogona kunge iri kune imwe nzvimbo.

Pakati pemitsetse yakafanana, kana iwe uine tafura yevatengesi vanhu, mashoko ose ari mutafura iyo inofanira kurondedzera zvakananga kune uyo munhu anotengesa. Chero humwe ruzivo rwakawedzerwa rwusingarevi kune uyo munhu akatengesa rungangodaro kune imwe nzvimbo mune dhesi yako.

Kunyange zvazvo tafura iyi ichitaridzika seyo yose yakabatanidzwa kune mumwe munhu mutengesi, iri chaizvo ine tafura yakaiswa mukati metafura. Cherechedza kuti Office uye OfficeNumber inodzokorora sei ne "Austin Downtown". Zvakadini kana nhamba yefoni yefaira ichichinja? Iwe unofanirwa kuvandudza sarudzo yose ye data kune imwe chikamu chimwe chemashoko ekuchinja, iyo isati iri chinhu chakanaka. Iyi minda inofanira kutamirwa patafura yavo pachayo.

Icho chimiro chekugadzira chinokupawo kukwanisa kuwedzera mamwe mashoko kune tafura yeHofisi pasina kusimbisa husiku hwemafutter mune tafura yekutengesa munhu. Fungidzira kuti inguva yakawanda basa raizova sei kuchengetedza rondedzero yekero remugwagwa, guta, nyika uye zip code kana yose iyo mashoko ari mukutengesa munhu tafura!

Database Mistake # 3: Kuisa Zvikamu Zviviri kana Zvimwe Zveruzivo Mundima Imwechete

Kubudisa mahofisi ehofisi mutafura yevatengesi yekutengesa yakanga isiri dambudziko rega re database. Munda wekero waiva nezvikamu zvitatu zvemashoko: kero yemugwagwa, guta nehurumende. Nzvimbo imwe neimwe mu database inofanira kunge iine chinhu chimwe chete chemashoko. Paunenge uine zvidimbu zvakasiyana zvemashoko mundima imwe, zvinogona kuva zvakaoma kuti uongorore dhesi rekuziva.

Semuenzaniso, zvakadini kana tichida kumhanya mubvunzo kune vose vanotengesa vanhu vanobva kuAustin? Tichazofanira kutsvaga mukati memunda wekero, izvo zvisiri izvo zvisiri izvo chete, asi zvinogona kutora mashoko akaipa. Pashure pezvose, chii chinoitika kana mumwe munhu aigara kuAustin mumugwagwa muPortland, Oregon?

Heino iyo tafura inofanira kutaridzika sei:

Pane zvinhu zvishoma kuti uone pano. Kutanga, "Address1" uye "Address2" zvingaratidzika kuwira pasi pezvakadzokorora masimi kukanganisa.

Zvisinei, munyaya iyi vari kutaura nezvezvikamu zvakasiyana zvemashoko zvinorondedzera zvakananga kune munhu anotengesa panzvimbo pane boka rinodzokorora deta rinofanira kuenda patafura yake.

Uyewo, sekanganiso yebhonasi yekudzivisa, cherechedza kuti kuumbwa kwenhamba yefoni kwakabviswa sei patafura. Iwe unofanirwa kudzivisa kuchengetedza maitiro eminda apo pazvinenge zvichibvira. Munyaya yefoni nhamba, pane nzira dzakawanda dzevanhu dzinyore nhamba yefoni: 215-555-5858 kana (215) 555-5858. Izvi zvinogona kutsvaga kutsvaga munhu anotengesa nhamba yefoni yavo kana kuita kutsvaga kwevatengesi vemuzana munharaunda imwechete code yakaoma zvikuru.

Dhiyabhorosi Mistake # 4: Kusashandisa Chinokosha Chakakosha

Mune zviitiko zvakawanda, iwe unoda kushandisa nhamba yekuwedzera inowanzoita kana imwe imwe inogadzirwa nhamba kana alphanumeric nokuda kwekona yako yekutanga. Iwe unofanirwa kudzivisa kushandiswa chero ruzivo rwechokwadi rwekona huru kunyange kana rinonzwika sekuti raizoita chiratidzo chakanaka.

Semuenzaniso, isu tose tine nhamba yedu yehutano yehupfumi, saka kushandiswa kwehuwandu hwekuchengeteka kwevanhu kune imwe nzvimbo yevashandi inogona kumira semafungiro akanaka. Asi kana zvisingawanzoitiki, zvinogona kuitika kunyange nhamba yekuchengeteka kwevanhu kuti ichinje, uye hatitombodi kuti chinokosha chedu chekutanga chekushandura.

Uye iyo ndiyo dambudziko nekushandisa mashoko chaiwo sechinhu chinokosha. Inogona kuchinja.

Dhiyabhorosi Mistake # 5: Kwete kushandisa Gungano rekudana

Izvi zvingasaita sechinhu chikuru kana iwe ukatanga kutanga kugadzirisa dhesi yako, asi kana wawana kusvika pakunyorera mibvunzo pamusoro pedheta rekutsvaga kuwana mashoko, kugamuchira kokorodzano kunyorera kuchakubatsira sezvaunoyeuka mazita emunda.

Chimbofungidzira kuti zvakaoma zvakadini kudai kwaizove kana mazita akachengetwa seNotName, LastName mune rimwe tafura uye kutanga_name, last_name mune imwe tafura.

Iyo mbiri mbiri dzinonyanya kuzivikanwa dzinomirira zita rekutanga yezwi rimwe nerimwe mumunda kana kuparadzanisa mazwi achishandura. Iwe unogona kuonawo vamwe vashanduri vanongedzera tsamba yekutanga yezwi rimwe kunze kweshoko rekutanga: firstName, lastName.

Iwewo unoda kusarudza kushandisa mazita ematafura asina kufanana kana mazita akawanda etafura. Ndiyo tafura yemutambo here kana kuti tafura yekurayira? Ndiyo tafura yevatengi kana tafura yevatengi here? Zvakare, haudi kuiswa neTable tafura uye tafura yevatengi.

Gungano rekusarudza raunosarudza harisi rakakosha sekugadzirisa kwekusarudza nekunamatira kune zita remagungano.

Dhiyabhorosi Mistake # 6: Inonyanya Kuenzanisira

Kunyoresa ndechimwe chezvinhu zvakaoma zvikuru kuti zvive zvakanaka, zvikuru kune avo vatsva pakusangana kwedhina. Zvose zvisikwa zvinokosha uye makiwo emunyika yekunze zvinofanira kuverengwa. Izvi ndizvo zvinobatanidza tafura pamwe chete, saka pasina chinyorwa, iwe uchaona kushaya hutano huripo kubva pane yako database.

Asi izvo zvinowanzosiyiwa ndezvimwe mimwe minda. Iyi ndiyo "WHERE" minda. Kana iwe kazhinji uchienda kunotsvaga kutsvaga kwako nekushandisa munda mune WHERE clause, unoda kufunga nezvekuisa mutsara mundima iyoyo. Zvisinei, haudi kunyanya kuisa tafura, iyo inogona kukuvadza kushanda.

Nzira yekugadzirisa sei? Ichi chikamu chehutano hwekugadzirwa kwepa database. Hapana mitsara yakaoma pamusoro pekuti ingani mitsara yaunofanira kuisa patafura. Kunyanya, iwe unoda kurondedzera chero imwe nzvimbo inowanzoshandiswa muchikamu che WHERE. Verenga zvakawanda pamusoro pekunyoresa zvakakodzera database yako.