Koj puas tuaj yeem siv cov lus qhia tsis tu ncua hauv SQL?
Koj puas tuaj yeem siv cov lus qhia tsis tu ncua hauv SQL?

Video: Koj puas tuaj yeem siv cov lus qhia tsis tu ncua hauv SQL?

Video: Koj puas tuaj yeem siv cov lus qhia tsis tu ncua hauv SQL?
Video: Raug koj tso los tsis ua cas _ by ntxawg lis Full song (2019.10.13)【chailee music】 2024, Kaum ib hlis
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Tsis zoo li MySQL thiab Oracle, SQL ntawv Server database ua tsis txhawb built-in RegEx muaj nuj nqi. Txawm li cas los xij, SQL ntawv Server muaj built-in functions los daws cov teeb meem nyuaj. Piv txwv ntawm cov haujlwm no yog LIKE, PATINDEX, CHARINDEX, SUBSTRING thiab REPLACE.

Ntawm no, dab tsi yog * hauv kev qhia tsis tu ncua?

* hauv lub ntiaj teb sib piv txhais tau tias "xoom lossis ntau dua ntawm ib tus cwj pwm", sau ua. *in ib kev qhia tsis tu ncua . Cov. dot cim tsis muaj lub ntsiab lus tshwj xeeb hauv lub ntiaj teb sib txuam: nws tsuas yog sawv rau nws tus kheej xwb.

Qhov thib ob, siv li cas muaj nyob rau hauv SQL? Muaj yog ib tug predicate siv nyob rau hauv qhov chaw ntawm ib tug Transact- SQL ntawv SELECT nqe lus los ua SQL ntawv Server full-text search on full-text indexed columns muaj hom ntaub ntawv raws tus cwj pwm. Muaj tuaj yeem tshawb rau: Ib lo lus lossis kab lus. Lub prefix ntawm ib lo lus los yog kab lus.

Ib yam li ntawd, cov lus hais li cas hauv Oracle?

Cov lus qhia tsis tu ncua pab kom koj tshawb nrhiav cov qauv hauv cov ntaub ntawv hlua los ntawm kev siv cov qauv kev sib txuas lus sib txuas. Koj teev a kev qhia tsis tu ncua los ntawm kev siv cov cim hauv qab no: Metacharacters, uas yog cov neeg ua haujlwm uas qhia txog kev tshawb nrhiav algorithms. Literals, uas yog cov cim uas koj yog

Dab tsi tsis zoo li SQL?

Cov TSIS ZOO tus neeg ua haujlwm hauv SQL ntawv yog siv rau ntawm kab uas yog hom varchar. Feem ntau, nws yog siv nrog % uas yog siv los sawv cev rau txhua txoj hlua tus nqi, suav nrog tus cwj pwm null. Txoj hlua peb hla mus rau tus neeg teb xov tooj no yog tsis yog case-sensitive.

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