Le ndatshana izongena ijule emhlabeni we-Oracle SQL, igxile kakhulu kumqondo 'wezixhumanisi zesizindalwazi', okwaziwa ngokuthi 'dblinks'. Lezi zici, ezibalulekile enqubweni yokuxhuma kanye nokusebenzisana nezingosi zolwazi, zisebenza njengengxenye ebalulekile yekhithi yamathuluzi kanjiniyela. Ngeke nje sichaze inkinga i-dbLinks ehlose ukuyixazulula, kodwa futhi sinikeza incazelo ejulile, yesinyathelo nesinyathelo yekhodi ehilelekile.
Inkinga: Ukuhlukaniswa Kwezingosi Zolwazi
yolwazi, ngokwemvelo yazo, ivame ukuba yizinhlangano ezizimele. Idatha yabo iqukethwe futhi ingafinyelelwa kuphela ngamasistimu abo angokwemvelo. Lokhu kuba yinkinga ezimeni lapho uzodinga ukufinyelela futhi ulawule idatha kusuka kuzinqolobane eziningi ngesikhathi esisodwa. Futhi lesi yisimo lapho i-dblink ingena khona.
- I-dbLinks ivumela isizindalwazi esisodwa (isizindalwazi sendawo) ukuthi sifinyelele amatafula kwenye isizindalwazi (isizindalwazi esikude).
- Inikeza ikhono lokudonsa idatha kusuka emithonjeni ehlukahlukene yokubika okuhlanganisiwe.
Ikhodi: Ukusebenzisa Isixhumanisi Sesizindalwazi
Sisebenzisa i-Oracle SQL, ake sihlole ukuthi umuntu angayisebenzisa kanjani i-dblink ukuxazulula le nkinga. Okulandelayo isibonelo esijwayelekile sokuthi umhleli angabhala kanjani ikhodi yalokhu:
DALA I-DATABASE LINK remote_db
XHUMANA KUmsebenzisi_we-remote IDENTIFIED BY remote_pw
UKUSEBENZISA 'remote_db';
Umsebenzi lapha ulula - lolu cezu lwekhodi lwakha isixhumanisi sesizindalwazi esisha esibizwa nge-'remote_db', bese sixhuma kuso kusetshenziswa igama lomsebenzisi elinikeziwe ('umsebenzisi_okude') kanye nephasiwedi ('remote_pw').
Note: 'remote_db' isibizo se-TNS sesizindalwazi esikude.
Ukuze ufinyelele ithebula kusizindalwazi esikude, umuntu angabhala ngale ndlela elandelayo:
KHETHA * KUSUKA ku-my_table@remote_db;
Izixhumanisi Zesizindalwazi: Imisebenzi Ebalulekile Nemitapo yolwazi
I-Oracle SQL ihlinzeka ngemisebenzi eminingana eyingqayizivele nemitapo yolwazi engasetshenziswa eduze kwezixhumanisi zesizindalwazi ukuze kuthuthukiswe ukusetshenziswa kwazo kanye nokusebenziseka kalula.
DBMS_SQL iwumtapo wezincwadi we-PL/SQL ohlinzeka ngoxhumano ku-SQL eguquguqukayo lapho ingakwazi ukuhlaziya noma yiluphi ulimi lokukhohlisa idatha (i-DML) noma isitatimende solimi lokuchazwa kwedatha (i-DDL) isebenzisa izakhiwo ezingafanele iphinde iyisebenzise.
Enye i- UTL_HTTP iphakheji, iphakheji ye-PL/SQL yokwenza izicelo ze-HTTP ku-Database ye-Oracle, ingasetshenziswa ngokuhambisana nezixhumanisi zesizindalwazi ukuze ufinyelele futhi ulawule idatha.
Ukuqonda nokusebenzisa ngempumelelo izixhumanisi zesizindalwazi kubalulekile kunoma yimuphi umthuthukisi we-Oracle SQL. Lapho usebenza nezingosi zolwazi eziningi, i-dbLinks ayivumeli kuphela ukufinyeleleka kwedatha kodwa futhi yethula amathuba engeziwe okuhlaziya nokuphatha idatha. Ngolwazi olufanele namathuluzi, ungasebenzisa ngokugcwele lokho okuhlinzekwa yisizindalwazi se-Oracle.
