Cov txheej txheem:

Koj ua li cas hauv SQL?
Koj ua li cas hauv SQL?

Video: Koj ua li cas hauv SQL?

Video: Koj ua li cas hauv SQL?
Video: 5nTears-ua li koj hais 2024, Kaum ib hlis
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Tsim Cov Lus Qhia

  1. CREATE [los yog REPLACE] TIG trigger_name - Tsim lossis hloov qhov uas twb muaj lawm ua rau nrog lub trigger_name.
  2. {Ua ntej | Tom qab | TSEEM CEEB OF} - Qhov no qhia tau tias thaum twg ua rau yuav raug tua.
  3. {INSERT [OR] | Hloov tshiab [OR] | DELETE} - Qhov no qhia txog kev ua haujlwm DML.

Ib yam li ntawd, nws tau nug, yuav ua li cas txheeb xyuas qhov tshwm sim hauv SQL Server?

Tau txais kev txhais lus txhais siv SSMS

  1. Ua ntej, hauv Object Explorer, txuas mus rau database thiab nthuav qhov piv txwv ntawd.
  2. Qhov thib ob, nthuav cov ntaub ntawv thiab cov lus uas muaj qhov ua rau koj xav pom qhov txhais.
  3. Thib peb, nthuav Triggers, right-click lub trigger koj xav saib lub ntsiab lus, thiab ces nias Hloov.

Tsis tas li ntawd, schema hauv SQL yog dab tsi? A schema hauv a SQL ntawv database yog ib qho kev sau ntawm cov qauv tsim cov ntaub ntawv. Los ntawm SQL ntawv Server 2005, a schema yog ib qho chaw ywj pheej (cov khoom ntim khoom) txawv ntawm tus neeg siv uas tsim cov khoom ntawd. Hauv lwm lo lus, schemas zoo ib yam li cais namespaces los yog ntim uas yog siv los khaws cov khoom database.

Kuj tseem paub yog, vim li cas thiaj siv cov cim hauv SQL?

Ua rau pab tus tsim database kom paub meej txog qee yam kev ua, xws li tswj xyuas cov ntaub ntawv tshawb xyuas, ua tiav tsis hais qhov program lossis tus neeg siv hloov pauv cov ntaub ntawv. Cov kev pab cuam hu ua ua rau txij li thaum ib qho kev tshwm sim, xws li ntxiv cov ntaub ntawv rau ib lub rooj, hluav taws lawv tua.

Dab tsi yog qhov pom hauv SQL?

Hauv SQL ntawv , a saib yog lub rooj virtual raws li qhov tshwm sim-teeb ntawm ib qho SQL ntawv nqe lus. Cov teb hauv a saib yog cov teb los ntawm ib lossis ntau lub rooj tiag tiag hauv cov ntaub ntawv. Koj tuaj yeem ntxiv SQL ntawv functions, WHERE, thiab JOIN cov nqe lus rau a saib thiab nthuav tawm cov ntaub ntawv zoo li cov ntaub ntawv tau los ntawm ib lub rooj.

Pom zoo: