- Idatha ephindaphindiwe ihlanekezela ukuhlaziywa nezinqumo, ngakho-ke kubalulekile ukuyithola nokuyilawula ngaphambi kokusebenza ngayo.
- Amaspredishithi afana ne-Excel akuvumela ukuthi ugqamise, uhlunge, futhi ususe okuphindwe kabili ngokuhlanganisa ukufometha okunemibandela, izihlungi ezithuthukisiwe, kanye nemisebenzi yombhalo.
- En yolwazi I-SQL, i-SELECT DISTINCT kanye nezinye izindlela ezifana ne-GROUP BY zisiza ekutholeni imiphumela ngaphandle kwemigqa ephindaphindwayo ngaphandle kokushintsha idatha yokuqala.
- Amathuluzi okuphatha izincwadi kanye nemikhuba emihle yokusekela kanye nokubuyekeza kusengaphambili kunciphisa ingozi yokulahlekelwa ulwazi olufanele ngokuqeda okuphindwe kabili.
Uma usebenza nama-database, amaspredishithi noma izinhlelo zolwazi, Idatha ephindaphindiwe ingaba yikhanda elibuhlungu ngempelaAmarekhodi aphindaphindwayo, amagama apelwe ngezindlela eziyinkulungwane ezahlukene, izinsuku ezingahlelwanga kahle, noma izikhala ezengeziwe kwenza ukuhlaziya kungathembeki futhi kuchitha isikhathi sakho uhlola ngesandla ukuthi yini uhlelo olungakusiza ukuyihlanza ngemizuzwana.
Izindaba ezinhle ukuthi zikhona Amathuluzi anamandla okuthola, ukugqamisa, nokususa idatha ephindaphindiwe kokubili ku-Excel kanye -Google Amashidi njengaku- Idatha ye-SQL noma amathuluzi okuphatha uhlu lwezincwadi. Ukuqonda ukuthi asebenza kanjani, ukuthi ahluke kanjani, nokuthi yiziphi izingozi azibekayo (njengokususa ulwazi ongase uluphuthe kamuva) kubalulekile ekugcineni idatha yakho ihlelekile futhi ukwazi ukuyihlaziya ngokuthula kwengqondo.
Kungani kuvela idatha ephindaphindwayo futhi kungani iyinkinga?
Ngokwenzayo, Amakhophi aphindaphindwayo avela emaphutheni abantu, ukungeniswa okuphindaphindiwe, noma izinhlelo ezingahambisani kahle.Amafomu athunyelwa kabili, amafayela ahlanganiswe ngaphandle kokuhlanzwa kwangaphambilini, noma ukuhlanganiswa phakathi kwezinhlelo zokusebenza ezingaqinisekisi kahle ulwazi kuyindawo ephelele yokuzalela uhlelo lwakho ukuze lugcwaliswe ngamarekhodi aphindwe kabili.
Ngaphandle kokuphindaphindwa okusobala, uzothola ukuhlukahluka okuncane okumelela idatha efanayoAmagama anezinhlamvu ezinkulu nezincane ezixubile, izikhala ezengeziwe, izifinyezo ezahlukene, noma izinsuku ezinefomethi ehlukene uhlelo olungazazi njengezifanayo, yize kusobala kumuntu ukuthi abhekisela entweni efanayo.
Umthelela ubalulekile: Izibalo ziphambene; inani lamakhasimende noma leziguli liyakhuphuka.Ama-imeyili ayaphindwa emikhankasweni ye-imeyili, ama-invoyisi ayaphindwa, noma inani lama-oda lilinganiselwa ngokweqile. Lokhu kungaholela ezinqumweni ezimbi, ezindlekweni ezengeziwe, kanye nokuntuleka okukhulu kokwethemba ikhwalithi yedatha.
Ngakho-ke, ngaphambi kokungena ekudaleni amadeshibhodi noma ukuhlaziya okuthuthukile, kufanelekile ukuchitha isikhathi ku- Ithuluzi elihle kakhulu lokuhlanza idatha lokuthola nokulungisa ukungahambisaniUkususa ama-duplicate kuyingxenye ebalulekile yale nqubo, kodwa akuyona yodwa: kufanele futhi hlanganisa umbhalo ngendlela efanayo, susa izikhala ezingajwayelekile bese ulungisa izinsuku.
Thola futhi ugqamise idatha ephindaphindiwe kumaspredishithi
Amathuluzi afana ne-Excel anikeza imisebenzi elula kakhulu ukuhlonza ngokushesha ukuthi yimaphi amanani aphindaphindwayo kuhlu lwamaseliNgaphambi kokususa noma yini, kuyalulekwa ukusebenzisa ifomethi ebonakalayo ekusiza ukuthi ubukeze futhi unqume ngokuthula ukuthi yini ofuna ukuyigcina.
Indlela evamile kakhulu yokuqala iwukuba... Ukufometha okunemibandela ukugqamisa amanani avela kaningiNgale ndlela, awushintshi okuqukethwe amaseli, umane uwaphawule ukuze ukwazi ukuwahlaziya.
Umsebenzi ojwayelekile uhilela ukukhetha kuqala amaseli okufanele abuyekezwe bese usebenzisa Umthetho wokufometha onemibandela ophawula okuphindwe kabili ngombala noma ifonti ehlukile yangemuvaLokhu kukuvumela ukuthi ubone amaphethini: isibonelo, ukubona ukuthi umuntu uvela kaningi ohlwini lwamakhasimende noma ukuthi amakhodi athile omkhiqizo abhaliswe kaningi.
Ngaphezu kwalokho, ungahlanganisa lokhu kugqamisa okuzenzakalelayo nezihlungi ngaphakathi kwespredishithi uqobo ukuze Buka imigqa ethintwe yizimpinda kuphela bese uyibuyekeza ngayinye ngayinye.Lokhu kukunika ukulawula futhi kunciphisa ingozi yokususa ulwazi olubalulekile ngengozi.
Susa ngokuphephile amanani aphindaphindiwe ku-Excel
Uma usucacile ukuthi yikuphi ukuphindaphinda okungadingeki, i-Excel ifaka umsebenzi othize obizwa ngokuthi "Susa ama-duplicates" asusa unomphela imigqa ephindaphindwayoYilapho okufanele uhambe khona ngokucophelela, ngoba lokho okususile akulula ukukuthola uma ungakayigcini ikhophi.
Ngaphambi kokusebenzisa leli thuluzi, kunconywa kakhulu Kopisha ububanzi bedatha yokuqala kwelinye ishidi noma ifayela eliyisipeleNgale ndlela, uma ukuhlanza kuveza umphumela ongalindelekile, ungabuyekeza lokho okususile bese uthola ulwazi ngaphandle kwezinkinga.
Inqubo isekelwe ekukhetheni ububanzi bamaseli ofuna ukuwahlanza bese ubonisa ukuthi yimaphi amakholomu okufanele aqhathaniswe kuwo ukuze kunqunywe ukuthi umugqa uphindwe kabili yini. Uma ukhetha amakholomu amaningi, umugqa kuphela onhlanganisela yawo ephelele efana nomunye umugqa ozobhekwa njengophindwe kabili.okuwusizo kakhulu lapho usebenza ngedatha eyinkimbinkimbi.
Uma iqinisekisa ukusebenza, i-Excel isusa imigqa eyengeziwe bese Ikukhombisa isifinyezo sokuthi zingaki izimpinda ezisusiwe nokuthi zingaki amarekhodi ahlukile asele.Lo mbiko omfushane uyakusiza ukuqinisekisa ukuthi imiphumela iyahambisana yini nalokho obekulindelekile ngesikhathi uqala ukuhlanza.
Kufanele kukhunjulwe ukuthi Ukuhlunga amanani ahlukile akufani nokususa ama-duplicate.Uma uhlunga, imigqa ephindaphindwayo ifihlwa okwesikhashana kuphela, kodwa isekhona; ukususa okuphindaphindwayo kuyayisusa ngokuphelele. Yingakho ukuqala ngesihlungi esiyingqayizivele noma ukufometha okunemibandela kuyisu elihlakaniphile.
Izindlela zokucabangela inani elizophindwa kabili
Uma amathuluzi espredishithi eqhathanisa okuphindwe kabili, Benza kanjalo ngokusekelwe kulokho okubonakala ngempela kuseli, hhayi enanini elihunyushwe ngaphansi.Lokhu kunemiphumela ethile exakile okudingeka uyazi ukuze ungatholi lutho olumangazayo.
Isibonelo, izinsuku ezimbili ezimele usuku olufanayo zingase zingabhekwa njengeziphindaphindiwe uma Elinye libhalwe ngokuthi “08/03/2006” kanti elinye libhalwe ngokuthi “Mashi 8, 2006”ngoba okuqukethwe kombhalo kuhlukile noma ngabe incazelo ifana. Kungenzeka okufanayo ngamagama nezintambo ezinezikhala noma izinhlamvu ezinkulu ezahlukene.
Ngokufanayo, inombolo egcinwe njengombhalo kanye nenombolo efanayo ngefomethi yezinombolo Zingaphathwa njengezingamanani ahlukene. Yingakho kubaluleke kakhulu ukwenza amafomethi abe ngokwejwayelekile ngaphambi kokuzama ukususa imigqa ephindaphindiwe ngobuningi.
Ngaphambi kokwenza ukuhlanza okunamandla, kufanelekile ukuhlunga kuqala amanani ahlukile noma ukusebenzisa ukufometha okunemibandela ukuqinisekisa. ukuthi inqubo yokuqhathanisa iyasebenza njengoba ukholelwaUkubeka le mithetho yomdlalo ekuqaleni kuvimbela ukulahlekelwa idatha esebenzayo noma ukushiya amakhophi afihliwe.
Umbhalo usebenza kumaspredishithi ukuhlanza idatha engcolile
Ingxenye enkulu yezinkinga ngama-duplicate ayiveli enanini elifanayo eliphindaphindwayo, kodwa eqinisweni lokuthi Ulwazi olufanayo lubhalwe ngezindlela ezihlukile kancaneYilapho imisebenzi yombhalo ye-Excel noma ye-Google Sheets isebenza khona ukuze kulungiswe futhi kulungiswe isisekelo ngaphambi kokususa ukuphindaphinda.
Kuvamile kakhulu ukuthola amakholomu lapho amanye amagama ebhalwe ngosonhlamvukazi, amanye ngosonhlamvukazi abancane, kanti amanye exutshwe ngokungahleliwe. Ukuze uwahlanganise, unemisebenzi ehambisanayo Baguqula yonke into ibe ngosonhlamvukazi abancane, yonke into ibe ngosonhlamvukazi abakhulu, noma babhale uhlamvu lokuqala lwegama ngalinye ngosonhlamvukazi abakhulu.Lokhu kuqinisekisa ukuthi u-“ANA PÉREZ”, u-“ana pérez” kanye no-“Ana Pérez” baphathwa ngendlela efanayo.
Imibhalo ene- izikhala ezengeziwe, kokubili ngaphakathi kweketanga kanye nasekuqaleni noma ekugcineniUmsebenzi okhethekile ungasusa izikhala ezengeziwe futhi ushiye isikhala esivamile phakathi kwamagama, ngaleyo ndlela ususe u-"Juan García" noma imishwana efanayo ephula ukuqhathanisa.
Ukuze uthole idatha ehlanganiswe ndawonye, njengamakhodi ahlanganisiwe noma amagama nezibongo kuseli elifanayo, kuyasiza ukusebenzisa imisebenzi yokukhipha kanye neyokuhlanganisa. Ungakwazi khipha ingxenye yombhalo okubonisa ukuthi ufuna ukukhipha izinhlamvu ezingaki noma ukuhlanganisa izintambo eziningana zibe yinye ukuze wakhe kabusha amasimu ahambisanayo.
Uma kwenzeka izinsuku, uma zifika njengombhalo onezitayela ezahlukene, kungumqondo omuhle ukuziguqula zibe ifomethi yedethi ejwayelekile esekelwe onyakeni, enyangeni, kanye nosukuNgale ndlela, amaspredishithi awaphatha njengezinsuku zangempela, ungawahlela kahle, futhi ukuqhathanisa akusaxhomekile ekubukekeni kweseli okubonakalayo.
Hlunga amanani ahlukile bese ususa okuphindwe kabili kumaspredishithi
Ngaphezu kwamathuluzi okufometha nemisebenzi yombhalo, kokubili i-Excel ne-Google Sheets zivumela Hlunga ngokushesha ukuze ubone amanani ahlukile kuphela kukholomu noma isethi yamakholomuLena indlela ephumelela kakhulu yokubukeza imiphumela ngaphambi kokwenza izinqumo ezingalungiseki.
Kwezinye izindawo, ungasebenzisa izinketho zokuhlunga ezithuthukisiwe ukukhombisa ukuthi ufuna kuphela ukubonisa imigqa enamanani ahlukile kukholomu eyodwa noma ngaphezulu ethize. Lokhu kuhlunga akususi idatha, kumane kufihla okwesikhashana okuphindwe kabili., okwenza kube yisinyathelo esiphakathi esihlakaniphile kakhulu.
Uma usuqinisekisile ukuthi umbono oyingqayizivele yilowo onentshisekelo kuwo, usuvele imiyalo ethize ye- Susa okuphindwe kabili ngqo kumamenyu edathaNgokuvamile, ufinyelela into efana nokuthi "Idatha > Susa Amakhophi Aphindaphindwayo", lapho ukhetha khona ukuthi yimaphi amakholomu ozosekela kuwo ukuqhathanisa.
Enye inketho ukusebenzisa ukufometha okunemibandela ukugqamisa kokubili amanani aphindaphindwayo kanye namanani ahlukile, kuye ngezidingo zakho. Isibonelo, ungenza lokhu: Gqamisa ngombala ogqamile imigqa evela kanye kuphela futhi uhlaziye ukuthi ngabe amarekhodi angavamile, amaphutha okulayisha, noma amacala angavamile okudingeka alondolozwe.
Uma usebenza ngohlu oluya phansi noma ukuqinisekiswa kwedatha, kunengqondo kakhulu ukuzihlanza nazo. Ungakwenza lokhu ngamamenyu okuqinisekisa. chaza uhlu oluvaliwe oluvimbela ukwethulwa kokwehluka kokuthayipha, ngaleyo ndlela kunciphisa ukuvela kwamakhophi angamanga empeleni angamaphutha okubhala.
Ukuhlanza okuphindwe kabili kudathabheyisi ye-SQL nge-SELECT DISTINCT
Ngesikhathi sisuka ezweni lamaspredishithi saya ezweni yolwaziIndlela ishintsha kancane. Ku-SQL, elinye lamathuluzi okuqala okuphatha ulwazi oluphindaphindwayo yi-opharetha I-DISTINCT, esetshenziswa kanye nomyalo we-SELECT wokubuyisela imigqa ngaphandle kokuphindaphinda emiphumeleni yombuzo.
Umqondo ulula: uma wakha isitatimende esithi SELECT, ungangeza igama elingukhiye elithi DISTINCT ukukhombisa lokho Ufuna ukwenzeka okukodwa kuphela kwenhlanganisela ngayinye yamanani kumakholomu akhethiwe. Ngale ndlela, uma umugqa ofanayo onengqondo uphindaphindwa izikhathi eziningana etafuleni, umbuzo uzobuyisa umugqa owodwa.
Kubalulekile ukuqonda ukuthi i-SELECT DISTINCT ayisusi lutho kudathabheyisi: Kuthinta kuphela umphumela owubonayo uma usebenzisa umbuzo.Ulwazi lokuqala alushintshile kumathebula, okuyinto ephelele ekuhlaziyeni okuhlolayo lapho ungafuni ukushintsha idatha okwamanje.
Ngokuphathelene ne-syntax, iphethini evamile iqukethe ukuhlanganisa i-SELECT DISTINCT nohlu lwamakholomu onentshisekelo kuwo, kulandelwe yisigaba se-FROM ukukhombisa ithebula futhi, ngokuzithandela, isigaba se-WHERE okufanele sihlungwe ngezimo ezithileNgale ndlela ungacela, isibonelo, amakhasimende ahlukile avela ezweni elilodwa kuphela noma imikhiqizo ehlukile evela esigabeni esithile.
Le ndlela iwusizo kakhulu uma ufuna ukunciphisa imiphumela ibe yimibhalo engakopishiwe, kungakhathaliseki ukuthi Thola uhlu lwamakhasimende ngaphandle kokuphindaphinda ngenxa yama-oda amaningi, bonisa uhlu lwamakhodi omkhiqizo ahlukile noma udale inani lezinto ezihlukile kusethi yedatha.
Umehluko phakathi kwe-DISTINCT nezinye izindlela zokugwema ukuphindaphindwa ku-SQL
Nakuba i-DISTINCT ne-UNIQUE zingase zizwakale zifana, Azidlali indima efanayo ngaphakathi kwe-SQL ecosystemI-DISTINCT isebenza ku-SELECT questions, ithinta imigqa ebuyisiwe; I-UNIQUE ivame ukuhlotshaniswa nemikhawulo encazelweni yamathebula, okubonisa ukuthi amasimu athile awakwazi ukuqukatha amanani aphindaphindwayo.
Ngaphezu kwalokho, ezimweni ezinedatha eningi, ukusebenzisa i-SELECT DISTINCT kungaba nzima kakhulu, ngoba Injini yedatha idinga ukuqhathanisa wonke amakholomu akhethiwe. ukuthola ukuthi yimiphi imigqa efanayo. Ematafuleni amakhulu noma amatafula anamakholomu amaningi, lokhu kungaba nzima.
Ngakho-ke, kwezinye izimo kufanelekile ukucabangela ezinye izindlela. Enye yezinto ezivame kakhulu ukusebenzisa GROUP BY ukuze uqoqe imigqa ngekholomu eyodwa noma ngaphezulu futhi usebenzise imisebenzi yokuhlanganisa (njenge-COUNT, MIN, noma i-MAX) ekuvumela ukuthi ufingqe idatha kahle.
Ungathembela futhi ezigabeni ezifana ne-EXISTS ze- hlola ukuthi amanani athile akhona yini kwelinye ithebulaLokhu kugwema ukuhlanganisa imigqa ephindaphindwayo engadingekile. Noma, ungasebenzisa imibuzo engezansi enezigaba ezichazwe kahle ezithi SELECT, FROM, kanye ne-WHERE ukuze ucacise kangcono ukuthi yimaphi amarekhodi ofuna ukuwathola.
Uma ufuna ukubala ukuthi zingaki izindinganiso ezihlukile ezikhona kukholomu, kuvamile ukuhlanganisa i-COUNT ne-DISTINCT, ukuze Uthola inani lezinto ezahlukene ngqo. ngaphandle kwesidingo sokuhlola ngayinye yazo ngesandla.
Izibonelo ezisebenzayo: imibuzo yamakhasimende namakheli angenazo izifanekiso ezifanayo
Cabanga ukuthi usebenza nethebula lama-oda lapho umugqa ngamunye umele khona okuthengiwe. Kuvamile ukuthi Ikhasimende elifanayo lizovela izikhathi eziningi uma lifake ama-oda angaphezu kwelilodwa.Uma ufuna ukubona ikhasimende ngalinye kanye kuphela, i-SELECT DISTINCT iyithuluzi elicacile kakhulu.
Kulesi simo, ungakha umbuzo okhetha amakholomu okuhlonza amakhasimende (isibonelo, i-ID yabo kanye negama labo) bese usebenzisa i-DISTINCT ku- thola uhlu neklayenti ngalinye kanye kuphela, yize ithebula lokuqala linezinhlawulo eziyishumi ezahlukene.
Kwenzeka okufanayo uma udinga ukubona konke amakheli okuthumela ahlukile lapho imikhiqizo ithunyelwe khonaUma i-oda ngalinye lifaka ikheli, ithebula lizogcwala ukuphindaphinda; noma kunjalo, nge-DISTINCT kumakholomu ekheli ungakha uhlu oluncane lwezindawo zokuthumela.
Uma ufuna ukugxila kumakhasimende avela endaweni ethile, ungangeza isigatshana esithi WHERE ukukhombisa, isibonelo, ukuthi Unentshisekelo kuphela kumarekhodi avela ezweni elithileNgale ndlela, i-SELECT DISTINCT isebenza engxenyeni encane yethebula, hhayi kuyo yonke idatha.
Emikhakheni yezempilo noma yezemfundo, umqhubi uwusizo kakhulu futhi idatha yeqembu evela ezigulini noma kubabhali abavela izikhathi eziningi ezifundweni noma ezihlokweni ezahlukene, okubonisa okufakiwe okukodwa kuphela ngenhlangano ngayinye ngezinjongo zokuhlaziya.
Ukuphatha izinkomba eziphindaphindwayo kudathabheyisi yezincwadi
Emkhakheni wemibhalo yesayensi, izizindalwazi zezincwadi ngokuvamile zinikeza amathuluzi athile okususa izinkomba eziphindaphindwayo Uma usesha emithonjeni ehlukene, lokhu kubalulekile ukuvimbela ukubuyekezwa kwezincwadi zakho ukuthi kungagcwali izihloko eziphindaphindwayo.
Kulezi zinhlelo, ngokuvamile kuba nomyalo othi "Susa okuphindwe kabili" ngaphakathi kwemenyu yamathuluzi, okuthi Ihlaziya isethi yemiphumela bese isusa ngokuzenzakalelayo izinkomba eziphindaphindwayo.Uhlelo luvame ukubika ukuthi zingaki izinto ezisusiwe nokuthi zingaki ezisele kusethi yamanje.
Kumapulatifomu amaningi ungawalungisa, kusukela esigabeni sezintandokazi, ukuthi Ukususwa kwezinkomba eziphindaphindiwe kwenziwa ngokuzenzakalelayo. isikhathi ngasinye lapho wenza usesho olusha. Lokhu kusindisa umsebenzi omningi wezandla, yize kunconywa ukuthi uhlole njalo ukuthi izindlela eziphindaphindwayo zilungile.
Ngaphezu kokususa ngobuningi, laba baphathi bakuvumela ukuthi ukhethe ngesandla izinkomba ezithile ukuze unqume ukuthi uzigcine noma uzisuse. Lokhu kubuyekezwa ngesandla kuyasiza lapho uhlelo lungaqiniseki ukuthi amarekhodi amabili empeleni ayinto efanayo. noma uma zihambisana nezinguqulo ezahlukene (isibonelo, okuphrintiwe ngaphambilini kanye nezinguqulo zokugcina).
Ngemva kokususa ama-duplicate, isethi yemiphumela iyabuyekezwa futhi kukhombisa inani elincishisiwe lezinkombaLokhu kulawula ngezinombolo kusiza ukuqinisekisa ukuthi ukususwa kwamaphutha kube nomthelela futhi kubhale phansi inqubo ekubuyekezweni okuhlelekile noma emibikweni yokusesha.
Umbhali oshisekayo ngomhlaba wamabhayithi nobuchwepheshe ngokujwayelekile. Ngiyathanda ukwabelana ngolwazi lwami ngokubhala, futhi yilokho engizokwenza kule bhulogi, ngikubonise zonke izinto ezithakazelisayo kakhulu ngamagajethi, isofthiwe, ihadiwe, izitayela zobuchwepheshe, nokuningi. Inhloso yami ukukusiza ukuthi uzulazule emhlabeni wedijithali ngendlela elula nejabulisayo.