Video: Dab tsi yog qhov tshwm sim hauv MySQL w3schools?
2024 Tus sau: Lynn Donovan | [email protected]. Kawg hloov kho: 2023-12-15 23:47
A ua rau yog ib txheej ntawm kev ua haujlwm uas tau ua tiav thaum lub sijhawm hloov pauv (SQL INSERT, UPDATE, lossis DELETE nqe lus) ua rau ntawm lub rooj teev tseg. Ua rau muaj txiaj ntsig zoo rau cov haujlwm xws li kev tswj hwm kev lag luam, kev lees paub cov ntaub ntawv tawm tswv yim, thiab ua raws li kev soj ntsuam. Cov ntsiab lus: Siv rau ua rau.
Kuj paub, dab tsi yog qhov tshwm sim hauv MySQL?
Cov MySQL pib yog ib qho khoom siv database uas cuam tshuam nrog lub rooj. Nws yuav qhib tau thaum ib qho kev txiav txim tau ua tiav rau lub rooj. Cov ua rau tuaj yeem ua tiav thaum koj khiav ib qho hauv qab no MySQL Cov nqe lus ntawm lub rooj: INSERT, UPDATE thiab DELETE thiab nws tuaj yeem raug hu ua ntej lossis tom qab qhov kev tshwm sim.
Qhov thib ob, dab tsi yog qhov sib txawv ntawm qhov tshwm sim hauv MySQL? Muaj 6 hom kev sib txawv hauv MySQL:
- Ua ntej hloov tshiab Trigger: Raws li lub npe txhais tau hais tias, nws yog qhov tshwm sim uas ua rau ua ntej qhov hloov tshiab raug hu.
- Tom qab hloov tshiab Trigger:
- Ua ntej Insert Trigger:
- Tom qab Insert Trigger:
- Ua ntej Delete Trigger:
- Tom qab Delete Trigger:
Tsis tas li ntawd, dab tsi tshwm sim hauv MySQL nrog piv txwv?
Hauv MySQL, qhov tshwm sim yog qhov kev zov me nyuam khaws cia hauv cov lus teb rau qhov xwm txheej xws li ntxig , hloov tshiab , los yog rho tawm uas tshwm sim nyob rau hauv cov txuam rooj . Piv txwv li, koj tuaj yeem txhais tau ib qho txiaj ntsig uas tau hais tawm ua ntej kab tshiab tso rau hauv a rooj.
Dab tsi yog qhov sib txawv ntawm qhov ua rau?
Hom Kev Txhaum Cai . Hauv SQL Server peb tuaj yeem tsim plaub hom kev cuam tshuam Cov Lus Txhais Lus (DDL) ua rau , Data Manipulation Language (DML) ua rau , CLR ua rau , thiab Logon ua rau.
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