Izingqinamba ezibalulekile zakwamanye amazwe ziyingxenye ebalulekile yokuphatha ubudlelwano kusizindalwazi. Ukungaqondi kahle noma ukuphatha kabi lezi zingqinamba kungaholela kudatha namaphutha anganembile. Ngakho-ke, kubalulekile ukubamba indlela yokuphatha lezi zingqinamba ngempumelelo. Ukusebenzisa amandla e-SQL kungasiza ukwenza lula le nqubo ngokunikeza indlela eqondile yokukhubaza izingqinamba zokhiye bangaphandle uma kudingeka.
I-SQL, noma i-Structured Query Language , ulimi lokuhlela olusetshenziswa ukuxhumana nokuphatha izizindalwazi. Naphezu kwamandla alo, kunezimo lapho kudingeka khona ukukhubaza umkhawulo wokhiye wangaphandle, ikakhulukazi lapho kwenziwa izinguquko ku-schema noma ngesikhathi sokusebenza kwedatha enkulu.
BEGIN; ALTER TABLE table_name NOCHECK CONSTRAINT constraint_name; /*run commands here*/ COMMIT;
Ukuqonda Ikhodi
Ikhodi engenhla iveza indlela eyisisekelo yokukhubaza ukhiye wangaphandle obambezelekile ku-SQL. Inqubo iqala ngesitatimende esithi BEGIN, esibonisa ukuqala komsebenzi we-SQL.
Okulandelayo, umyalo we-ALTER TABLE usetshenziselwa ukuguqula incazelo yethebula. Lokhu kulandelwa isitatimende se-NOCHECK CONSTRAINT. Lo myalo othize ukhubaza ukhiye wangaphandle obambezelekile, empeleni utshela i-SQL Server ukuthi ingahloli izithiyo zokhiye wangaphandle ngenkathi isebenzisa izitatimende zika-INSERT, UPDATE, noma DELETE.
Umsebenzi uphetha ngesitatimende se-COMMIT, esiphothula noma yiziphi izinguquko ezenziwe kusizindalwazi phakathi nomsebenzi.
Izithiyo Ezibalulekile Zangaphandle Kokusebenza
Uma isetshenziswe kahle, imikhawulo yokhiye bangaphandle ingaqinisekisa ubuqotho bedatha yakho. Nokho, kunezimo lapho kudingekile ukukhubaza lezi zingqinamba okwesikhashana. Isibonelo, ungase udinge ukufaka ngenqwaba idatha yokungenisa isuka komunye umthombo, futhi le datha ingase ingabambeleli ngokuqinile ebudlelwaneni obuchazwe kusizindalwazi sakho.
Kulesi simo, ukukhubaza izithiyo zokhiye bangaphandle kukuvumela ukuthi ungenise idatha ngaphandle kwezihibe. Uma ukungenisa sekuqediwe, ungaphinda unike amandla izithiyo futhi ulandele inqubo yokuhlanza ukuze ulungise noma yikuphi ukungahambisani.
Imitapo yolwazi kanye nemisebenzi ehilelekile
Awekho amalabhulali engeziwe noma imisebenzi edingekayo ukuze usebenzise le miyalo ye-SQL ngokusetha okujwayelekile. Imiyalo ethi ALTER TABLE, BEGIN, COMMIT, kanye ne-NOCHECK CONSTRAINT yakhelwe ku-SQL futhi kufanele itholakale kunoma yikuphi ukusetha okujwayelekile kweseva ye-SQL.
Khumbula ukuthi ukuze usebenze kahle, kubalulekile ukuba nokuqonda okuqinile kwe-schema sesizindalwazi sakho, amagama amathebula namakholomu, nokuthi yiziphi izithiyo ezisetshenziswa lapho.
Ukunamathela isu eliqinile lokuphatha isizindalwazi kubalulekile. Ngakho-ke, ukwazi ukunika amandla noma ukukhubaza izithiyo zokhiye bangaphandle kuvumela ngempumelelo ukuguqulwa kwe-schema sesizindalwazi kanye nokusebenza kahle kwedatha yenqwaba. Ngalolu lwazi, ungafinyelela ukulawula okukhulu ekusebenzeni kwakho kwesizindalwazi futhi uthuthukise ubuqotho buphelele bedatha yakho.
