Cov txheej txheem:

Yuav ua li cas koj sau ib qho ntawm nqe lus hauv SQL?
Yuav ua li cas koj sau ib qho ntawm nqe lus hauv SQL?

Video: Yuav ua li cas koj sau ib qho ntawm nqe lus hauv SQL?

Video: Yuav ua li cas koj sau ib qho ntawm nqe lus hauv SQL?
Video: Vim li cas koj lub neej thiaj li tsis txawj muaj nyiaj yog ua cas? ( How to Change your life) 2024, Kaum ib hlis
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SQL ntawm Syntax

SELECT Kem (s) NTAWM table_name NTAWM KAM NTAU tus nqi1 THIAB tus nqi2; Siv cov lus hais saum toj no syntax , peb tuaj yeem txhais cov nqi raws li ib feem ntawm BETWEEN tus neeg teb xov tooj . Tsis tas li ntawd, cov syntax hais los saum toj no tseem zoo ib yam rau kev siv nrog tus lej lej, tus nqi ntawv, thiab hnub tus nqi.

Tsis tas li ntawd, koj ua li cas ntawm nqe lus hauv SQL?

Cov nqi ua tau yog cov ntawv, hnub tim, lossis tus lej. Nws ua tau siv rau hauv SELECT, INSERT, UPDATE, lossis DELETE nqe lus . Cov SQL BETWEEN Cov xwm txheej yuav xa rov qab cov ntaub ntawv uas qhia nyob rau hauv thaj tsam ntawm tus nqi 1 thiab tus nqi 2.

zoo li nqe lus hauv SQL li cas? SQL ntawv - LIKE Clause . Kev tshaj tawm. Cov SQL LIKE clause yog siv los sib piv tus nqi rau zoo sib xws tus nqi siv cov neeg ua haujlwm wildcard. Muaj ob lub wildcards siv ua ke nrog cov LIKE tus neeg ua haujlwm.

Ib yam li ntawd, kev siv ntawm cov lus txib yog dab tsi?

Lub SQL NTAU xwm txheej tso cai rau koj sim yooj yim yog hais tias ib qho kev qhia nyob rau hauv ib tug ntau yam ntawm qhov tseem ceeb (inclusion). Nws tuaj yeem siv tau hauv SELECT, INSERT, UPDATE, lossis DELETE nqe lus.

Dab tsi ua hauv SQL?

SQL IN mob (qee zaum hu ua IN tus neeg teb xov tooj) tso cai rau koj los sim yooj yim yog tias qhov kev qhia cuam tshuam ib qho nqi hauv cov npe ntawm qhov tseem ceeb. Nws yog siv los pab txo qhov kev xav tau ntau yam LOSSIS nyob rau hauv SELECT, INSERT , HLOOV TSHIAB, lossis DELETE nqe lus.

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