Sezvo wakasiyiwa SQL-Sorting?

Kana tichishanda Databases kazhinji zvakakodzera kuti kuona kuti mubvunzo mugumisiro mune imwe kuti Somuenzaniso alphabetically. Kuti aite izvi, ari DBMS ane basa rinokosha SQL - Sorting. Panyaya iyi, iyo programmer anogona kusarudza iyo minda uye umo kuti zvichava kuita zvinodiwa mugumisiro pasina kushandisa chakakomba zvirongwa unyanzvi.

Chii arongwe mune Database?

Kushanda Databases zviri kugara rwakabatana huru Vhoriyamu mashoko, izvo zvinokosha kuona hurongwa. Pari zvino pane zvinoverengeka Databases, ine zvakawanda features, inonyanya kufarirwa zvacho Oracle uye MS SQL. Sort mashoko somumwe huru nzira iri Database, akapa vane chaiwo yakavakwa-mumwe nomumwe wavo.

chepamusoro date kurerutsa tsvaga kwacho, uye dzimwe nguva, kubatsira kugadzirisa zvimwe zvinetso kana optimize kushanda chirongwa. SQL-kufambira nokuda munda yoga vakasarudzwa, uye kana zvakakodzera, panyaya tsika dziri pezvokuvamba munda uyu anogona kuratidza yokuwedzera zviruva, izvo kuona nzvimbo parukungiso.

kworudzii murayiro

SQL-kufambira ari Database inopiwa kuburikidza nokushandisa KUTI BY mabasa. Nokudaro, Kunyange zvazvo kwakabva mashoko kubva Database, mushure iwe kutaridzwa matafura uye mbiru vachaitwa kuverenga kubva iyo, chikumbiro anofanira kutaridzwa kworudzi murayiro, uye ibva waona munda kana minda kuti zvichaita arongwe.

Somuenzaniso, kana tafura Vanhu vanofanira kuwana umboo kubva kuminda Name uye Age, panguva imwecheteyo kuratidza kunoguma earufabheti kweZita mbiru, zvichabatsira kuti zvinotevera mubvunzo: Sarudza Name, Age FROM People KUTI BY Name.

Sei kuisa worudzii murayiro?

Current ezvinhu pozi programmers mabasa akasiyana-siyana, uye dzimwe nguva zvakakodzera kuti akafanosarudza hurongwa umo tinoguma kuoneka - kuburikidza akwira kana nokuburuka hurongwa, alphabetically kana nekwekupedzesera? Uye nokuda kuti SQL kworudzi kuti kunotemwa nokuwedzera shoko guru riri mubvunzo. Mushure kusarudza minda uye matafura iro zvaaida mashoko inotengwa, zvakakodzera kuwedzera KUTI BY, ipapo kutaridzwa zita mbiru uchida kugadzirisa pairi.

Nokuti nekwekupedzesera unofanira kutaridzwa zita mushure parameter Desc. Kana vaviri streamline kudiwa zvakawanda zvinodiwa, ipapo mbiru dzakaparadzaniswa nezvitura befu, uye pakutanga chepamusoro kana munda kunopiwa chokwadi kuti pokutanga iri pasi. Zvinofanira kucherechedzwa kuti inogara zvinhu nekwekupedzesera parameter Desc kunopa munda mumwe chete, pashure iyo zita rakapiwa guru iri, saka kana uchida zvakafanira kuti tsanangurai kusarudzwa mbiru dzose.

Alternative nzira kufambira

Kana pasina mukana kushandisa pakuvara SQL-Sorting, unogona kunyora rimwe anozivikanwa algorithms. Kana zvakakodzera, kuti awane uchitsanya arayira okunze, vanofanira kushandisa nzira "anokurumidza zvemarudzi", inobva hafu-nokuputsa kuko. Also nhaka kukurumbira makuru kuera kuti "sefuro" umo zviviri pedyo zvinhu zviri kunoshandurwa mu nyaya urongwa kururama, "HeapSort" anotumira chikuru chinhu pakuguma pamazita, uyewo "kupinza worudzii" predetermining nzvimbo nechimwe chine maatomu akafanana akavapindurawo.

Zvisinei, rugwaro rwakanyorwa nemaoko kunyora kuti algorithm haazobvumiri kuti yekudyidzana kuwedzera nokukurumidza kufambira achabatsirawo kuti kukura mapurogiramu unyanzvi, asi vo kuzobvumira yokugadziridza neurongwa nokugadzirisa chepamusoro zano vamwe Database kuvandudza kunyatsoshanda purogiramu.