Kodi Funso lachidule ndi chiyani?

Mafunso akugwiritsira ntchito mphamvu yanu

Funso lochokera ku deta lachinsinsi la deta kuchokera ku databata ndikulikonzekera mwachidule. Funso liyenera kulembedwa m'chinenero chomwe deta ikufunira-kawirikawiri, chinenerocho ndi SQL .

Mwachitsanzo, pamene mukufuna deta kuchokera ku deta, mumagwiritsa ntchito funso kuti mufunse zomwe mukufuna. Mwina muli ndi tebulo la antchito, ndipo mukufuna kufufuza malonda ogwira ntchito. Mungathe kufunsa funso lanu kwa wogwira ntchitoyo yemwe analembapo malonda apamwamba kwambiri panthawi inayake.

SQL SELECT Statement

Funso lachinsinsi liyenera kutsata machitidwe omwe akufunidwa ndi database. Chizolowezi chofala kwambiri ndi mtundu wa Structured Query Language (SQL) yofunikirako yofunikirako yomwe amagwiritsidwa ntchito ndi machitidwe ambiri otsogolera ma database. SQL ndi chinenero champhamvu chomwe chingathe kufunsa mafunso apamwamba.

SQL imagwiritsa ntchito mawu osankhidwa kuti asankhe deta yeniyeni.

Taganizirani chitsanzo chochokera ku deta ya Northwind yomwe nthawi zambiri imatulutsidwa ndi zinthu zamtunduwu monga maphunziro.

Pano pali ndondomeko yochokera pa gome la ogwira ntchito:

Kubwezeretsa dzina la mwini wake ndi dzina kuchokera ku deta, ndondomeko ya SELECT idzawoneka ngati izi:

SANKANI Dzina Loyamba, Dzina Loyamba, Mutu KU Ogwira Ntchito;

Idzabwerera:

Kuti muyese zotsatirazo moonjezera, mukhoza kuwonjezera chiganizo cha WHERE:

SANKANI NTHAWI YOTSOPANO, Dzina Loyamba Kuchokera kwa Ogwira Ntchito

PAMENE Mzinda = = 'Tacoma';

Amabwezeretsa Woyamba ndi Winawake wa Wothandizira aliyense wochokera ku Tacoma:

Onani kuti SQL imabweretsanso deta mu fomu / khomo fomu yomwe ili yofanana ndi Microsoft Excel, yopangitsa kuti ikhale yosavuta kuiwona ndikugwira nawo ntchito. Zinenero zina zoyeserera zingabweretse deta monga graph kapena tchati.

Mphamvu ya Mafunsowo

Mndandanda wachinsinsi umatha kuwulula zovuta ndi zochitika zovuta, koma mphamvu izi zimagwiritsidwa ntchito pogwiritsa ntchito funsolo. Mndandanda wovuta kwambiri umakhala ndi matebulo angapo akusunga zambirimbiri za deta. Funso limakulolani kuti muliyese mu tebulo limodzi kuti mutha kuliwerenga mosavuta.

Mafunsanso angathe kupanga mawerengedwe pa deta yanu kapena kusintha zochita zadongosolo. Mukhozanso kuyang'ananso kusintha kwa deta yanu musanawapereke ku databata.