Cov txheej txheem:
Video: Cov lus nug ntawm kev nkag yog dab tsi?
2024 Tus sau: Lynn Donovan | [email protected]. Kawg hloov kho: 2023-12-15 23:47
A nug yog ib qho kev thov rau cov ntaub ntawv tau txais, thiab rau kev nqis tes ua ntawm cov ntaub ntawv. Koj tuaj yeem siv a nug los teb ib lo lus nug yooj yim, ua kev suav, muab cov ntaub ntawv los ntawm cov rooj sib txawv, lossis tseem ntxiv, hloov, lossis tshem tawm cov ntaub ntawv rooj. Lus nug uas ntxiv, hloov, lossis tshem tawm cov ntaub ntawv yog hu ua kev nqis tes ua lus nug.
Ntxiv mus, koj sau cov lus nug hauv kev nkag li cas?
Txhawm rau tsim cov lus nug yooj yim ib- rooj:
- Xaiv qhov Tsim tab ntawm Ribbon, thiab nrhiav pawg Queries.
- Nyem qhov Query Design hais kom ua.
- Kev nkag mus yuav hloov mus rau Query Design view.
- Nyem Ntxiv, ces nyem Kaw.
- Cov lus xaiv yuav tshwm sim raws li lub qhov rais me me hauv Object Relationship pane.
peb hom lus nug yog dab tsi? Nws yog feem ntau lees paub tias muaj peb hom kev tshawb fawb sib txawv:
- Cov lus nug navigational.
- Cov ntaub ntawv tshawb nrhiav.
- Cov lus nug nrhiav kev lag luam.
Ib yam li ntawd, hom lus nug hauv Access yog dab tsi?
Hmoov zoo rau peb, Microsoft Nkag mus tso cai rau ntau hom lus nug , qee qhov tseem ceeb yog xaiv, ua, parameter thiab aggregate lus nug . Lawv tuaj yeem xav tias yog lwm qhov ntawm koj cov ntaub ntawv - qhov tseem ceeb ntawm cov khoom xws li lub rooj lossis macro.
Cov lus nug yooj yim yog dab tsi?
DEFINITION: A lus nug yooj yim yog a nug uas tshawb nrhiav siv ib qho parameter xwb. A lus nug yooj yim tej zaum yuav siv tag nrho cov teb nyob rau hauv ib lub rooj thiab nrhiav siv ib tug parameter xwb. los yog nws yuav siv tsuas yog qhov tsim nyog teb uas yuav tsum tau muaj cov ntaub ntawv, tab sis nws tseem yuav siv tsuas yog ib qho parameter (nrhiav cov qauv)
Pom zoo:
Dab tsi ntawm cov hauv qab no yog qhov zoo ntawm kev siv cov khoom siv pom kev hauv kev hais lus?
Qhov txiaj ntsig tseem ceeb ntawm kev siv cov khoom siv pom hauv koj cov lus hais yog tias lawv ua kom cov neeg tuaj saib muaj kev txaus siab, hloov kev mloog ntawm tus neeg hais lus, thiab ua rau tus neeg hais lus muaj kev ntseeg siab ntau dua hauv kev nthuav qhia tag nrho
Dab tsi yog cov lus nug siv los tso saib tag nrho cov npe ntawm cov ntxhuav hauv SQL Server?
Muaj ob txoj hauv kev los nrhiav txhua lub npe ntawm lub rooj, thawj qhov yog siv "QHOV" lo lus tseem ceeb thiab qhov thib ob yog los ntawm kev nug INFORMATION_SCHEMA
Dab tsi yog lub tswv yim los tswj cov kev txwv ntawm kev nkag mus ntawm cov peev txheej thaum ntau cov xov raug tua hauv Redis?
xauv Khaws qhov no hauv kev txiav txim siab, Redis ua li cas nrog kev sib raug zoo? Ib qho kev pabcuam ib leeg tuaj yeem muab tau sib npaug ntawm I / O qib los ntawm kev siv I / O (de) multiplexing mechanism thiab lub voj xwm txheej (uas yog dab tsi Redis ua ).
Yuav ua li cas koj tuaj yeem txav qhov taw tes nrawm nrawm mus rau qhov pib ntawm cov lus nug cov lus nug?
T lossis F: Nias Ctrl + txoj cai xub yuam sij kom txav qhov taw tes rau qhov pib ntawm lo lus tom ntej
Puas yog kev sau cov haujlwm uas tsim cov lus teb rau GraphQL cov lus nug?
Txhawm rau teb cov lus nug, schema yuav tsum muaj kev daws teeb meem rau txhua qhov chaw. Qhov kev sau ua haujlwm no hu ua 'resolver map'. Daim ntawv qhia no hais txog cov schema teb thiab hom rau ib txoj haujlwm