Sula irekhodi le-SQL ukuthi ungakwenza kanjani kahle?

Funda ukuthi kanjani sula ilogi ye-SQL ukugcina ikhompyutha yakho nohlelo olusebenzayo lulungiselelwe, konke ngale ndatshana kanye nolwazi lwayo olukhulu.

susa-qopha-i-sql-2

Lungiselela iqembu lakho ngendlela engcono kakhulu

Kungani usula i-log ye-SQL?

Lapho amakhompyutha enesistimu yokusebenza enezici ezithile eziyinhloko, okungukuthi, imemori ye-RAM ephansi, phakathi kuka-1GB noma u-2GB, neprosesa enesitoreji esiphansi, kuholela ekutheni uhlelo lube nezinto eziningi kwimemori luqala ukunamathela.

Irejista ye-SQL igcwalisa inkumbulo ngayo yonke imininingwane yayo, futhi ngenxa yalokho, le nombolo eyengeziwe yamafayela ingeza kulokho okubambezela uhlelo.

Ngokususa lonke lelo rekhodi, ingxenye yomsebenzi iqembu okufanele ilicubungule isusiwe, okwenza uhlelo luhleleke kakhudlwana.

Uyini umbhalo we-SQL?

Yimisebenzi eyenziwa kuseva ye-SQL. Iseva ye-SQL yilezo ezilawula ukuhamba kwemininingwane, okungukuthi, igcina lonke ulwazi inkampani olugcinayo.

Ukusebenza okwenziwayo kungamarekhodi emininingwane ephethwe izinkampani, ngalinye lalawa marekhodi liyacutshungulwa futhi ligcinwe kuseva. Kunamafayela ahlukene atholakala kuseva ye-SQL, ukuxhasa konke lokhu kucindezelwe futhi kukhonjiswe njenge-Log File, kuhlukaniswe ngokulandelana Amafayela Wokungena Okubonakalayo noma Amafayela Wokungena Okubonakalayo.

Amafayela we-log ebonakalayo adalwe ngokweqile, ngoba asebenzela ukonga idatha yedatha ye-SQL futhi, ngakho-ke, isitoreji sigcwele ngokwengeziwe, kube yinto embi ohlelweni. Ingabonakala nxazonke, ukuyihlukanisa namanye amafayela.

Amafayela we-log ebonakalayo asebenzisa inqubo yokuncishiswa, lokhu kusho ukuthi amafayela asevele asetshenzisiwe ayasetshenziswa, abekwa ekuphumuleni futhi amiswe isikhashana. Ngemuva kwalokho, ifayela seliqediwe, liyasetshenziswa futhi futhi inqubo iyaqhubeka ngale ndlela, njengomjikelezo.

Kuyini ukuthengiselana?

Ukuthengiselana kungamafayela wolwazi anokuqukethwe okuvela kumaseva we-SQL. Ifayela lokuthengiselana njengoba kuchaziwe, ligcinwa kufolda ehlukile futhi ilogi ehlukaniswayo iyakhiwa.

Ifayela lokuthengiselana libalulekile, ngoba yilona elisiza ukwenza izipele, uma kwenzeka okuthile kulahleka kuseva ye-SQL. Iyashintshwa noma ngabe ifayili lisetshenziswe malini, ngoba icindezelwe ukukwazi ngalo lonke ulwazi.

Imibhalo igcina amatafula, angabahleli abenziwe ngumsebenzisi, lapho inkambu namarekhodi ahlukaniswa khona, uku-oda imininingwane ukuthi ihambelane nomsebenzisi.

Inkambu yigama elisetshenziselwe ikholamu eyinhloko yolwazi, okuyidatha eyinhloko yokuhlukanisa namanye amatafula. Amarekhodi ayimigqa ehlukene engabhala itafula futhi ibe nolwazi lwezinkambu ezisungulwe ngumsebenzisi.

Kungasuswa nini ilog transaction?

Ifayela lokuthengiselana lingasuswa, uma kungenandaba ukuxazulula isiphakeli futhi uma ufuna ukususa kuphela ukuvula isikhala kuhlelo. Ngaphezu kwalokho, ungenza ikhophi nge-hard disk noma ulithumele kuseva yewebhu lapho bengagcina khona konke okuphathelene neseva ye-SQL.

Kunemininingwane engeke isuswe, ngoba uhlelo lwe-SQl luzoyeka ukusebenza, ngakho-ke, kufanele siqaphele lawa marejista ukuze singathinti uhlelo, kepha uhlelo olufanayo luzokutshela ukuthi leli fayela liyasetshenziswa hhayi lona susa.susa-qopha-i-sql-3

Ungayisula kanjani i-log ye-SQL?

Ngemuva kokuchaza ukuthi irekhodi le-SQL liqukethe ini, manje singaqhubeka nokuchaza ukuthi singalisusa kanjani, sithathe zonke izinyathelo ezidingekayo, esezichaziwe kakade.

  1. Kufanele ufake iseva ye-SQL, lapha singahlela noma senze izinguquko esicabanga ukuthi ziyadingeka kuseva yethu.
  2. Kakade kuseva ye-SQL, kuzosetshenziswa umyalo othi DELETE, ovame ukukhonza ukuqeda noma yiluphi uhlobo lwenqubo kwezinye izinhlelo. Eyaziwa nangokuthi umbuzo wokususa, isusa yonke idatha, kepha ayiqedi itafula.
  3. Izofakwa ngomyalo othi DELETE: "SUSA KU-table_name WHERE column1 = 'value'" (Ngaphandle kwezingcaphuno.)
  4. Uzofaka i- "DELETE FROM table_name", Ezothola itafula, eliqukethe irekhodi le-SQL, ngakho-ke, lonke ulwazi.
  5. Umyalo othi "WHERE column1 = 'value'" usetshenzisiwe, irekhodi eliphelele lingatholakala ukuze likwazi ukuliqeda ngqo. I- "WHERE" ikuvumela ukuthi ubeke umkhawulo ekususweni kwerekhodi, elihambisana nezici esizicelayo.
  6. Kubalulekile ukuthi wazi ukuthi uma "LAPHO" kungabekwanga njengoba kunje noma kungacaciswanga ngendlela efanele, amarekhodi esifisa ukuwagcina angaqedwa. Ukwakhiwa kwetafula kuzogcinwa, kepha ngeke kube nohlobo lolwazi.
  7. Gcina engqondweni ngemuva kokubhala amakhodi namarejista, ukuthi ngeke uphinde uthole noma yini esusiwe, ngakho-ke, hlola kahle uma kungekho okususiwe okudingekayo.
  8. Manje, kuzobekwa igama letafula elizosuswa, isibonelo: "DELETE FROM songs", ngaphandle kohlobo lwephutha.
  9. Ngemuva kwalokho, kuzobhalwa ikholomu ezosuswa, okungukuthi, ukwahlukaniswa kwemininingwane esiyenze etafuleni, isibonelo: «WHERE Rock = 'value'«.
  10. Ekugcineni, inani elibhaliswe esigabeni setafula liyabhalwa, okungukuthi, ukwahlukaniswa kwemininingwane eyenziwe, isibonelo: «WHERE Rock = 'jungle'«.
  11. Ukuqoshwa okuphelele kuzoba okulandelayo: «SUSA KWEZINGOMA LAPHO IDwala = 'inani'«. Izinyathelo ezifanayo ziphindaphindwa kaningi ngangokunokwenzeka ukuqeda yonke idatha.

Uma uyithandile le ndatshana, ngikumema ukuthi ufunde mayelana: "Uhlelo lokuphathwa kwedatha lwenzelwe ini?", okuthunyelwe okuchazayo ngalolu hlobo lohlelo, ngiyazi ukuthi uzoyithanda.


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  1. Ubhekele idatha: I-Actualidad Blog
  2. Inhloso yedatha: Lawula Ugaxekile, ukuphathwa kwamazwana.
  3. Ukusemthethweni: Imvume yakho
  4. Ukuxhumana kwemininingwane: Imininingwane ngeke idluliselwe kubantu besithathu ngaphandle kwesibopho esisemthethweni.
  5. Isitoreji sedatha: Idatabase ebanjwe yi-Occentus Networks (EU)
  6. Amalungelo: Nganoma yisiphi isikhathi ungakhawulela, uthole futhi ususe imininingwane yakho.