Puas yog mssql case rhiab?
Puas yog mssql case rhiab?

Video: Puas yog mssql case rhiab?

Video: Puas yog mssql case rhiab?
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SQL Server yog, los ntawm default, cas insensitive; txawm li cas los xij, nws muaj peev xwm tsim tau ib qho cas - sensitive SQL Server database thiab txawm los ua cov kab lus tshwj xeeb case sensitive . Txoj hauv kev los txiav txim siab seb cov ntaub ntawv lossis cov khoom siv database yog kuaj xyuas nws cov khoom "COLLATION" thiab nrhiav "CI" lossis "CS" hauv qhov tshwm sim.

Ib yam li ntawd, puas yog SQL case rhiab?

10 Teb. Cov SQL ntawv Keywords yog cas - insensitive (XEEM, LOS NTAWM, NTAU, thiab lwm yam), tab sis feem ntau sau rau hauv txhua lub kaus mom. Txawm li cas los xij hauv qee lub rooj teeb tsa thiab kab npe yog cas - rhiab heev . MySQL muaj qhov kev xaiv teeb tsa los pab / lov tes taw nws.

Tsis tas li ntawd, kuv tuaj yeem qhia tau li cas yog tias MySQL yog case sensitive? Table npe hauv MySQL yog cov ntaub ntawv system nkag, yog li lawv cas insensitive if lub hauv paus ntaub ntawv system yog. 0 - tsab ntawv teev tseg hauv CREATE TABLE lossis CREATE DATABASE nqe lus. 1 - Cov npe ntawm cov lus tau muab tso rau hauv cov ntawv me ntawm disk thiab cov npe sib piv tsis yog case sensitive.

Tib neeg kuj nug, Kuv yuav ua li cas SQL cov ntaub ntawv rhiab?

Case insensitive SQL SELECT: Siv cov haujlwm sab saud lossis qis dua xaiv * los ntawm cov neeg siv uas qis dua (first_name) = 'fred'; Raws li koj tau pom, tus qauv yog mus ua daim teb uas koj tab tom nrhiav rau hauv tus lej loj lossis tus lej me, thiab tom qab ntawd ua koj txoj hlua nrhiav kuj yog tus tsiaj ntawv loj lossis tus lej me kom phim rau SQL ntawv muaj nuj nqi koj tau siv.

Puas yog cov peev tseem ceeb hauv SQL?

SQL ntawv Case rhiab heev: Cov SQL ntawv Cov ntsiab lus tseem ceeb yog cov ntaub ntawv tsis txaus ntseeg (XL, NTAWM, NTAU, NTAU NTAWV, AS, ORDER BY, HAVING, GROUP BY, thiab lwm yam), tab sis feem ntau yog sau rau hauv tag nrho. peev . Txawm li cas los xij, hauv qee lub rooj teeb tsa thiab cov npe kab ntawv yog qhov tseem ceeb. MySQL muaj qhov kev xaiv teeb tsa los pab lossis lov tes taw nws.

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