Hom ntaub ntawv twg yog tiag?
Hom ntaub ntawv twg yog tiag?

Video: Hom ntaub ntawv twg yog tiag?

Video: Hom ntaub ntawv twg yog tiag?
Video: pua yog tim aib pog ntawv by zoo siab paj vuam sonie cover 2024, Lub peb hlis ntuj
Anonim

Tiag tiag . Ib ' Tiag tiag ' hom ntaub ntawv yog tus lej cov ntaub ntawv uas muaj cov lej lej. Nws yuav siv thaum xav tau kev nthuav dav ntxiv thiab tus lej tag nrho yuav tsis muab cov ntaub ntawv txaus.

Ua raws li qhov no saib, dab tsi yog hom ntaub ntawv tiag tiag hauv SQL?

Cov ntaub ntawv tiag tuaj yeem tuav tus nqi 4 bytes loj, txhais tau tias nws muaj 7 tus lej ntawm qhov tseeb (tus lej ntawm tus lej mus rau sab xis ntawm tus lej lej). Nws tseem yog tus lej ntab ntab uas zoo ib yam rau cov lus taw qhia ntab ntab ntab (24).

Ib yam li ntawd, cov ntaub ntawv hom piv txwv yog dab tsi? A hom ntaub ntawv yog a hom ntawm cov ntaub ntawv . Qee yam hom ntaub ntawv suav nrog integers, floating point tooj, cim, hlua, thiab arrays. Tej zaum lawv kuj yuav hais meej dua hom , xws li hnub tim, timestamps, boolean qhov tseem ceeb, thiab varchar ( sib txawv tus cwj pwm) formats.

Kuj kom paub yog, dab tsi yog tus lej tiag cov ntaub ntawv?

A hom ntaub ntawv tiag yog a hom ntaub ntawv siv nyob rau hauv ib tug computer program los sawv cev ib qho approximation ntawm a tus lej tiag . Vim lub tus lej tiag tsis suav tau, khoos phis tawj tsis tuaj yeem sawv cev rau lawv raws nraim siv cov ntaub ntawv tsawg kawg nkaus. Feem ntau, lub computer yuav siv qhov kev kwv yees kwv yees rau a tus lej tiag.

Dab tsi yog hom ntaub ntawv tiag tiag hauv C?

Cov no yog qhov tseem ceeb hom ntaub ntawv hauv C xws li integer(int), floating point(float), character(char) and void.

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