Ingaba usebenza kunye nedata ephethe iirekhodi zamanqaku okanye izigidi zeerekhodi, ukulungiswa kwedatha efanelekileyo kubalulekile. Akukuphela nje ukubuyisela ulwazi olulula kakhulu, kuya kwenza kube lula ukwandisa ulwazi kwixesha elizayo. Ngelishwa, kulula ukuwela kwiimigibe ezimbalwa ezingenza izinto zibe nzima kwixesha elizayo.
Kukho iincwadi ezibhaliweyo ezibhalwe kwisigxina se-database, kodwa ukuba uphephe nje ezi mpazamo eziqhelekileyo, uya kuba yindlela efanelekileyo yokuyila i-database.
Ikhonkco yeNgcaciso # 1: Imida yokuphinda kwiThebhile
Umgaqo osisiseko wesohlwayo sokwakheka kwedatha efanelekileyo kukubona ukuphinda idatha kunye nokubeka ezo kholomu kwitafile zazo. Ukuphindaphinda amaseshingi etafileni kuyaqhelekileyo kwabo bavela kwihlabathi lamaspredishithi, kodwa ngelixa iipredishithi zihlala zithe cwaka ngoyilo, i-yolwazi kufuneka ibe nobuhlobo. Kufana nokuhamba ukusuka kwi-2D ukuya kwi-3D.
Ngenhlanhla, iindawo eziphindaphindiweyo ziqheleke lula ukuzibona. Khawucinge nje kule tafile:
| I-OrderID | Umkhiqizo1 | Umkhiqizo2 | Umkhiqizo3 |
| 1 | Bears Bears | Ubhontshisi beJelly | |
| 2 | Ubhontshisi beJelly |
Kwenzeka ntoni xa umyalelo unemiveliso emine? Sifuna ukudibanisa enye intsimi etafileni ukuxhasa iimveliso ezingaphezulu kwezinto ezintathu. Kwaye xa sakha isicelo somthengi malunga netafile ukusinceda idatha yenkalo, sinokudinga ukuyiguqula ngentsimi yomkhiqizo omtsha. Kwaye sifumana njani yonke imiyalelo ngeJellybeans ngendlela? Siyakunyanzeliswa ukuba sicele yonke intsimi yomkhiqizo etafileni ngesitatimende se-SQL esinokubonakala ngathi: SEBENZA * KWEEMveliso OKUNYE UMveliso1 = 'Iibhontshisi zeJelly' OKANYE UMSEBENZI2 = 'Iibhontshisi zeJelly' OKANYE UMSEBENZI3 = 'Iibhontshisi zeJelly'.
Esikhundleni sokuba netafile enye edibanisa yonke ingcaciso kunye, kufuneka sibe neetafile ezintathu ukuba nganye ibambe iqela leenkcukacha. Kulo mzekelo, siza kufuna i-Orders itafile ngolwazi malunga nomyalelo ngokwawo, Ithebula leMveliso kunye nayo yonke imveliso yethu kunye neTebhethi ye-ProductOrders edibanisa iimveliso kumyalelo.
| I-OrderID | CustomerID | Umhla woMyalelo | Iyonke |
| 1 | 7 | 1/24/17 | 19.99 |
| 2 | 9 | 1/25/17 | 24.99 |
| ProductID | Mveliso | Bala |
| 1 | Bears Bears | 1 |
| 2 | Ubhontshisi beJelly | 100 |
| ProductOrderID | ProductID | I-OrderID |
| 101 | 1 | 1 |
| 102 | 2 | 1 |
Phawula indlela itafile nganye eneenkcukacha ze-ID ezahlukileyo. Le yintloko ephambili. Sidibanisa iitheyibhile ngokusebenzisa ixabiso eliphambili eliphambili njengekona langaphandle kwelinye itafile. Funda ngaphezulu malunga nezicwangciso eziphambili kunye nezitshixo zangaphandle.
Ikhonkco yeNgcaciso # 2: Ukufakela iThebhile kwiThebhile
Le yenye impazamo eqhelekileyo, kodwa ayisoloko ivele ngokucacileyo njengemihlaba ephindaphindiweyo. Xa uceba idatha, ufuna ukuqiniseka ukuba yonke idatha etafileni ihambelana nayo. Kufana nomdlalo womntwana malunga nokubona into eyahlukileyo. Ukuba unobhanana, i-strawberries, i-peach kunye nesethelevishini, umboniso wethelevishini mhlawumbi ungowinye indawo.
Ngaphandle kwemizila efanayo, ukuba unetafile yabantu abathengisayo, yonke ingcaciso kwitafile kufuneka ibhekise ngqo kuloo mntu uthengisayo. Naluphina ulwazi olongezelelweyo olungafani naloo mntu uthengisayo, unokuhlala kwenye indawo kwi-database yakho.
| SalesID | Ekuqaleni | Gqibela | Idilesi | Inombolo yomnxeba | Ofisi | OfficeNumber |
| 1 | Sam | Elliot | 118 I-St Main, Austin, TX | (215) 555-5858 | Austin Downtown | (212) 421-2412 |
| 2 | Alice | Smith | 504 I-2nd Street, eNew York, NY | (211) 122-1821 | ENew York (eMpuma) | (211) 855-4541 |
| 3 | Joe | IParish | 428 Aker St, Austin, TX | (215) 545-5545 | Austin Downtown | (212) 421-2412 |
Nangona le tafile ibonakala ngathi ihambelana nomthengisi ngamnye, inene ithala edibeneyo ngaphakathi kwetafile. Phawula indlela i-Ofisi ne-OfficeNumber iphinda ngayo "ne-Austin Downtown". Kuthekani ukuba inombolo yefowuni iyatshintsha? Uya kufuneka uhlaziye isethi yonke yedatha enye yecandelo elilodwa lokuguqulwa kolwazi, okungekho nto enhle. Ezi ndawo kufuneka zihanjiswe kwitafile zazo.
| SalesID | Ekuqaleni | Gqibela | Idilesi | Inombolo yomnxeba | OfficeID |
| 1 | Sam | Elliot | 118 I-St Main, Austin, TX | (215) 555-5858 | 1 |
| 2 | Alice | Smith | 504 I-2nd Street, eNew York, NY | (211) 122-1821 | 2 |
| 3 | Joe | IParish | 428 Aker St, Austin, TX | (215) 545-5545 | 1 |
| OfficeID | Ofisi | OfficeNumber |
| 1 | Austin Downtown | (212) 421-2412 |
| 2 | ENew York (eMpuma) | (211) 855-4541 |
Olu hlobo loyilo lunikeza amandla okongeza ulwazi olongezelelweyo kwiTheyibhile yeHhovisi ngaphandle kokudala i-nightmare ye-clutter kwitheyibhile yomntu wokuthengisa. Khawucinge ukuba wawube ngumsebenzi onjani ukugcina ingqalelo kwidilesi yesitalato, isixeko, i-state kunye nekhodi ye-zip ukuba yonke loo ngcaciso yayisetafile yomntu wokuthengisa!
Ikhonkco yeNgcaciso # 3: Ukubeka iiCandelo ezimbini okanye ngaphezulu kweNkcukacha kwiNgqungquthela eyodwa
Ukufakela ulwazi kwiofisi kwitheyibhile yomntu wokuthengisa kwakungeyona yodwa ingxaki kule database. Intsimi yedilesi iqulethe iinkcukacha ezintathu: idilesi yesitalato, isixeko kunye nombuso. Intsimi nganye kwisiseko sedatha kufuneka iqulethe enye ingcezu yolwazi. Xa unamacandelo amaninzi eenkcukacha kwintsimi enye, kunokuba nzima ukubuza imibuzo kwiziko leenkcukacha.
Ngokomzekelo, kuthekani ukuba sifuna ukuqhuba umbuzo kubo bonke abantu abathengisayo baseAustin? Sifuna ukukhangela ngaphakathi kwisebe yedilesi, engekho nje kuphela, kodwa inokubuyisela ulwazi olubi. Emva koko, kwenzeka ntoni ukuba umntu ehlala e-Austin isitalato ePortland, eOregon?
Nantsi into efunekayo itekisi ifana nayo:
| SalesID | Ekuqaleni | Gqibela | Idilesi 1 | Idilesi2 | Sixeko | Lumente | I-Zip | Ifowuni |
| 1 | Sam | Elliot | 118 I-St | Austin | TX | 78720 | 2155555858 | |
| 2 | Alice | Smith | 504 2nd St | Inew york | NY | 10022 | 2111221821 | |
| 3 | Joe | IParish | 428 Aker St | Apt 304 | Austin | TX | 78716 | 2155455545 |
Kukho izinto ezimbalwa ukuphawula apha. Okokuqala, "Idilesi1" kunye ne "Idilesi2" iya kubonakala iphantsi kweendawo eziphindaphindiweyo.
Nangona kunjalo, kule meko ba bhekisa kwiingcezu zeedatha ezihlukileyo ezihambelana ngokuthe ngqo kumntu othengisayo kunokuba iqela eliphindayo lwedata elifanele lihambe kwitafile yalo.
Kwakhona, njengempembelelo yebhonasi ukuphepha, qaphela indlela ukufometha kwenombolo yefowuni ikhutshwe kwi tafile. Kufuneka ugweme ukugcina ifomathi yeenkalo xa kunokwenzeka. Kwimeko yeenombolo zefowuni, kukho iindlela ezininzi zabantu abhala inombolo yefowuni: 215-555-5858 okanye (215) 555-5858. Oku kuza kwenza umntu othengisayo ngeenombolo zabo zefowuni okanye enze ukukhangela abantu abathengisayo kwikhowudi yendawo efanayo nzima kunzima.
Ikhonkco yeData yeNgcaciso # 4: Ukusebenzisa iCandelo eliPrayimari elichanekileyo
Kwiimeko ezininzi, uya kufuna ukusebenzisa inombolo yokuzenzekelayo ngokuzenzekelayo okanye enye inamba evelisiweyo okanye i-alphanumeric kwisitshixo esisisiseko. Kufuneka ugweme ukusebenzisa nayiphi na inkcazelo engundoqo yintloko ephambili nangona ivakala ngathi yayiza kwenza i-identifier efanelekileyo.
Ngokomzekelo, ngamnye siba nenani lomntu wokhuseleko loluntu, ngoko usebenzisa inombolo yezokhuseleko loluntu kumgca-nkcukacha wesisebenzi kunokuvakala njengengcamango efanelekileyo. Kodwa ngelixa kunqabile, kunokwenzeka ukuba nenombolo yokhuseleko yoluntu ishintshile, kwaye asifuni ukuba isisiseko sethu sitshintsho sitshintshe.
Yaye yile ngxaki ngokusebenzisa ulwazi oluchanekileyo njengexabiso eliphambili. Iyakushintsha.
Ikhonkco yeData yeNgcaciso # 5: Ungasebenzisi iSivumelwano segama
Oku kusenokungathi kuluphawu olunzulu xa uqale uqala ukuyila i-database yakho, kodwa xa ufika kumbango wokubhala ngokubhekiselele kwisiseko sedatha ukuze ufumane ulwazi, ukuba nomhlangano wonikezelo uza kunceda njengoko ukhumbuza amagama enkundla.
Khawucinge nje ukuba kunzima kangakanani loo nkqubo ukuba ngaba amagama agcinwe njengoNokuqala, i-LastName kwitheyibhile enye kunye neyokuqala_name, last_name kwelinye itafile.
Iindibano ezimbini ezibalulekileyo eziqeshwe ngegama lithetha i-letter yokuqala yegama ngalinye entsimini okanye ukwahlula amagama usebenzisa i-underscore. Ungabona nabathuthukisi abathile ukuba bahlaziye incwadi yokuqala yegama ngalinye ngaphandle kwegama lokuqala: lokuqalaName, LastName.
Uyakufuna ukugqiba nokusebenzisa amagama asetafile angamanye okanye amagama etafile. Ingaba itafile yeNkundla okanye iTheyard Orders? Ingaba itheyibhile yabaThengi okanye ithenda yabaThengi? Kwakhona, awufuni ukunamathela kwitafile ye-oda kunye neetafile zabaThengi.
Iindibano ezikhethiweyo ezikhethiweyo azibalulekanga njengenkqubo yokukhetha ngokwenene nokunamathela kwindibano yegama.
Ikhonkco yeData yeNgcaciso # 6: Iingxelo ezingalunganga
Ukuboniswa kolwazi ngenye yezinto ezinzima kunokuba zilungele, ingakumbi kulabo abatsha kwi-design design. Zonke izitshixo ezisisiseko kunye neefowuni zangaphandle kufuneka zihlawulwe. Le yile nto edibanisa itafile kunye, ngoko ke ngaphandle kwesiqulatho, uza kubona ukusebenza kakubi kakhulu kwi-database yakho.
Kodwa ziphi na izinto eziqhelekileyo eziphosakeleyo ezinye iindawo. Le yimihlaba ethi "YINI". Ukuba udla ngokunciphisa uphando lwakho ngokusebenzisa insimu kwisiqendu SAPHOHLU, ufuna ukucinga ngokubeka isalathisi kule ntsimi. Nangona kunjalo, awufuni ukutshintsha ngaphezulu itafile, ezinokuthi zonakalise ukusebenza.
Unokugqiba njani? Le nxalenye yobugcisa bokuyila idatha. Akukho mida enzima kumanqaku amaninzi ofuna ukuwabeka phezu kwetafile. Okokuqala, ufuna ukutsalathisa nayiphi na intsimi esetyenziswa rhoqo kwisiqendu SAPHO. Funda ngokubanzi ngokuchaneka ngokufanelekileyo kwi-database yakho.