Nakuba lesi sicelo singena emininingwaneni ethile mayelana nokuhlela i-athikili ehlobene ne-SQL kanye nokuthuthukisa i-SEO yayo, kubalulekile ukuqaphela ukuthi lokhu akuphathelene nezitayela zemfashini noma izinhlanganisela zezingubo njengoba kushiwo esicelweni sokuqala. Nokho, ngizokunikeza isihloko esihlobene ne-SQL ngokwezidingo zakho:
Umhlaba wokuphathwa kwedatha nezinhlelo zedathabheyisi kade ubuswa yi-SQL. I-SQL, noma Ulimi Oluhlelekile Lombuzo, isetshenziselwa ukuxhumana kanye nokukhohlisa imininingwane yolwazi. Kujwayelekile phakathi kwezinhlelo eziningi zokuphatha isizindalwazi esihlobene.
Ukuqalisa imibuzo ku-SQL ngempumelelo nangendlela efanele akulula ngaso sonke isikhathi njengoba kubonakala. Umehluko phakathi kwendlela efanele nengalungile ungathinta kakhulu ukusebenza kohlelo lwakho lwedathabheyisi. Imfihlo ilele ekubhaleni imibuzo elungiselelwe kahle nehlelekile.
Ukubhala Okuphumelelayo Kwemibuzo ku-SQL
Ukuze ubhale imibuzo esebenzayo ye-SQL, udinga ukuqala ngokuqonda idatha yakho kanye nomphumela ofisa ukuwuthola. Uma uziqonda kangcono lezi zici ezimbili, imibuzo yakho izoba yimpumelelo kakhulu.
SELECT column FROM table WHERE condition
Ikhodi engenhla iyisibonelo esilula sombuzo we-SQL.
QAPHELA
Enye yezindlela ezinhle kakhulu zokuhlaziya ukusebenza kombuzo ku-SQL ukusebenzisa umyalo we-EXPLAIN. Umyalo we-EXPLAIN unikeza ukubheka okujulile kokuthi imibuzo yakho ye-SQL isetshenziswa kanjani, okungakusiza ukuthi uyilungiselele ukusebenza okungcono.
EXPLAIN SELECT column FROM table WHERE condition
Ukwengeza INCAZELO ngaphambi kombuzo kukunikeza ukuqonda kokuthi umbuzo uzokwenziwa kanjani nokuthi yini ongayenza ukuze uwulungiselele.
izinkomba
Njengoba nje inkomba yezincwadi ikusiza ukuthi uthole okuqukethwe ngokushesha, inkomba yesizindalwazi ithuthukisa ukusebenza kwemibuzo yakho ye-SQL ngokunciphisa ukusebenza kwe-disk I/O.
CREATE INDEX index_name ON table(column)
Ukudala inkomba kukholamu ovame ukuyibuza akugcini nje ngokuthuthukisa isivinini sombuzo, kodwa futhi kunciphisa kakhulu umthwalo womsebenzi wesistimu.
Sengiphetha, i-SQL inikezela ngamathuluzi ahlukahlukene nemiyalo ukusiza onjiniyela baqhube imibuzo ephumelelayo. Ngokwazi ukubhala kahle imibuzo, usebenzisa umyalo othi CHAZELA ukuze uqonde ukuthi imibuzo yakho iphathwa kanjani, futhi usebenzisa izinkomba lapho kudingeka khona, ungakwazi ukuguqula indlela amasistimu akho esizindalwazi aphathwa ngayo.
