MySQL sarudza kubva vakasarudzwa: zvakabudiswa opareta

MySQL, somumwe ndeyeukama Database utariri hurongwa, ane wayo maumbirwo mharidzo Sarudza mashoko. Izvi hazvishamisi, nokuti Databases zvine zvakavanzika mashoko anyanye dzosa kana zvakakodzera. select from SELECT позволяет делать это множеством различных способов, предоставляя большой набор инструментов. MySQL sarudza kubva Sarudza mashoko kunoita kuti uite izvi nenzira dzakasiyana, ichipa boka guru maturusi.

kugadzwa MySQL

MySQL iri rakatangwa sezvo pasi Windows, uye pasi Linux. Kuisa MySQL Ubuntu, kuita zvikwata zviviri zvakanaka panguva chinouraya of Os:

- Sudo unoziva-kuwana gadza mysql-Server.

- Sudo unoziva-kuwana gadza mysql-nemhosva.

For MySQL Windows, chete kukopa kubva yepamutemo yepaIndaneti "Database" rakakodzera kugadzwa Mabhokisi uye kumhanya navo.

Zvinonyatsorehwa nemamiriro sarudza mashoko

Complete mamiriro muna MySQL sarudza kubva Sarudza mashoko ari sezvinotevera:

1. Sarudza - Mbiru mazita (minda).

2. FROM - tafura mazita.

3. KUPI - mamiriro iri mharidzo.

Ona kuti kunyange zvazvo SQL mutauro nemarongerwo haisi nyaya-nehanya, muitiro wakanaka kunyora mashoko uye reserved Keywords (FROM, KUPI, etc.) huru tsamba, uye mazita matafura neshongwe - diki. SELECT приведен на рисунке ниже. The muenzaniso kupfuura nyore kushandisa MySQL opareta vakasarudzwa kubva sarudza pasi apa.

An asiterisiki pashure shoko kusarudza ndiko analogue pamusoro guru ALL zvinoreva kuti kubva patafura rakapiwa kusarudza mbiru dzose. Kana uchifarira chete vamwe paminda tafura, vanofanira sezvinoratidzwa munzvimbo rakakodzera, akaparadzaniswa nevanhu nezvitura befu. Izvi zvinoshandawo mazita matafura - kana kupfuura mumwe, kupinda vose akaparadzaniswa nevanhu nezvitura befu.

Kushandisa KUPI

Zviri pachena, imi kugona kubatsira asi cherechedzai kuti chakapfuura muenzaniso, hapana guru KUPI - izvi nokuti iyi ndiyo tisingafaniri. Mashoko aya haana zvaida, uye vakadaro optioneel dzaishandisa muna vakasarudzwa, kune vazhinji, asi ivo vari zvishoma kwapera. Kana uri pashure zita inowedzera KUPI tafura uye chero ezvinhu akadai mhando = 'imbwa', ipapo mugumisiro yakatarwa achawana mutsara mumwe chete chete mhuka pachinzvimbo Edison. The Nhamba pazasi inoratidza muenzaniso. Regai Vasinehanya mashoko KUTI BY, pano hazvina basa, uye ichakurukurwa gare gare.

Zvinokosha kucherechedza kuti mushure KUPI Zvinogonekawo kunyora ezvinhu akawanda, asi haasisina akaparadzaniswa nevanhu nezvitura befu. Nokuti chinangwa ichi, unofanira kushandisa mazwi akadzama zvakadai AND kana OR. Zvose zvinoenderana sei mamiriro ako anofanira akasangana. Kana uchifarira Izvi kuti zvinogutsa ose ezvinhu iwe tsanangurai, ipapo pakati pavo kunge UYE, kana mugumisiro inofanira kugutsa pane mumwe wavo, ipapo kushandisa OR.

KUTI BY muvaravara

We vanotaurwa kuti kuwedzera KUPI ari Sarudza mashoko kune dzimwe mazvi zhinji izvo unogona konzera kuti mugumisiro wakaiswa sezvo zvaida neimwe ezvinhu. Mumwe akadaro "kiyi" ndiyo KUTI BY. Kunoitawo kuti kugadzirisa migumisiro mharidzo mukati imwe munda, zvose vachikwira nekuburuka. Zviri zvakakwana chete kutaridzwa mbiru zita muchimutevera, maererano netsika kuti unofanira kugadzirisa humboo. Zvakakosha kuti zvinoenderana ezvinhu akawanda: kutanga - zita raanotaura mashoko, KUTI BY, uye anofanira kuva muna sarudza; rechipiri - KUTI BY anofanira kuiswa panoperera chikumbiro.

The default worudzii ari kukwira (Asc), asi kana unofanira kugadzirisa zvabuda mu achiburuka kuitira, nyora pashure munda zita pachinzvimbo Asc guru Desc.

mhedziso

Taiongorora chikuru, asi kwete vose zvokushandisa zviri opareta MySQL sarudza kubva. Sarudza, tisingabatanidzi vaya ambotaurwa, ane zvakawanda zvimwe zvinhu kuti kubvumira kuti dzosa umboo kubva Database, flexibly chinovhiringidza.