Cov txheej txheem:
- Qhov zoo thiab qhov tsis zoo ntawm kev pom hauv SqlServer
- Cov hauv qab no yog qhov zoo ntawm kev siv databaseviews
Video: Kev pom thiab qhov zoo ntawm kev pom yog dab tsi?
2024 Tus sau: Lynn Donovan | [email protected]. Kawg hloov kho: 2023-12-15 23:47
Saib muaj peev xwm muab qhov zoo saum rooj: Saib tuaj yeem sawv cev rau ib pawg ntawm cov ntaub ntawv muaj nyob hauv atable. Yog li ntawd, a saib tuaj yeem txwv qhov kev cuam tshuam ntawm cov rooj hauv qab mus rau lub ntiaj teb sab nraud: tus neeg siv tau txais kev tso cai los nug cov lus nug. saib , thaum tsis kam nkag mus rau therest ntawm lub hauv paus rooj.
Hais txog qhov no, qhov zoo ntawm kev pom yog dab tsi?
Qhov zoo thiab qhov tsis zoo ntawm kev pom hauv SqlServer
- Kev ruaj ntseg. Txhua tus neeg siv tuaj yeem raug tso cai nkag mus rau hauv cov ntaub ntawv tsuas yog los ntawm ib pawg me me ntawm kev pom uas muaj cov ntaub ntawv tshwj xeeb uas tus neeg siv tau tso cai pom, yog li txwv tus neeg siv nkag mus rau cov ntaub ntawv khaws cia.
- Query Simplicity.
- Cov qauv yooj yim.
- Data Integrity.
- Logical cov ntaub ntawv ywj pheej.
- Kev ua tau zoo.
Dab tsi yog kev pom hauv SQL Dab tsi yog siv qhov pom? A saib Qhov tseeb yog qhov muaj pes tsawg leeg ntawm lub rooj nyob rau hauv daim ntawv ntawm ib tug predefined SQL ntawv nug. Views yog siv rau kev ruaj ntseg lub hom phiaj nyob rau hauv databases, views txwv tus neeg siv los ntawm saib tej kem thiab kab txhais tau tias yog siv saib peb tuaj yeem thov qhov kev txwv ntawm kev nkag mus rau cov kab tshwj xeeb thiab kab ke rau cov neeg siv tshwj xeeb.
Kuj paub, dab tsi yog qhov zoo ntawm kev pom hauv SQL Server?
Cov hauv qab no yog qhov zoo ntawm kev siv databaseviews
- Kev pom cov ntaub ntawv tso cai rau koj kom yooj yim cov lus nug nyuaj: adatabase saib yog txhais los ntawm SQL nqe lus uas koom nrog ntau cov lus hauv qab.
- Kev pom database pab txwv cov ntaub ntawv nkag mus rau cov neeg siv tshwj xeeb.
- Ib qho kev pom database muab txheej txheej kev ruaj ntseg ntxiv.
Dab tsi yog saib thiab nws qhov zoo hauv DBMS?
A DBMS muab lub moj khaum rau kev ua kom zoo dua ntawm cov ntaub ntawv ntiag tug thiab kev ruaj ntseg cov cai. Kev nkag tau dav dua towell-tswj cov ntaub ntawv txhawb kev sib koom ua ke saib ntawm lub koom haum kev khiav hauj lwm thiab ib tug clearer saib ntawm lub bigpicture. Nws ua tau yooj yim dua kom pom tias kev nqis tes ua hauv ib ntu ntawm lub tuam txhab cuam tshuam li cas rau lwm ntu.
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 qhov txawv ntawm kev sib raug zoo unary kev sib raug zoo binary thiab kev sib raug zoo ternary?
Kev sib raug zoo tsis sib xws yog thaum ob tus neeg koom hauv kev sib raug zoo yog tib lub koom haum. Piv txwv li: Cov ncauj lus yuav yog qhov yuav tsum tau ua ua ntej rau lwm yam kev kawm. Kev sib raug zoo ternary yog thaum peb lub koom haum koom nrog kev sib raug zoo
Dab tsi yog sparse kem Dab tsi yog qhov zoo thiab qhov tsis zoo?
Koj poob 4 bytes tsis yog ib zaug ib kab; tab sis rau txhua lub cell hauv kab uas tsis yog null. Qhov zoo ntawm SPARSE kem yog: Qhov tsis zoo ntawm SPARSE kem yog: SPARSE kem tsis tuaj yeem siv rau ntawm cov ntawv, ntext, duab, timestamp, geometry, geography lossis cov neeg siv cov ntaub ntawv teev tseg
Dab tsi yog qhov zoo thiab qhov tsis zoo ntawm kev tshaj xov xwm hauv kev kho mob?
Thaum siv ceev faj, kev tshaj xov xwm tuaj yeem muab cov txiaj ntsig zoo xws li kev sib tham ua haujlwm, kev kawm kho mob, thiab cov neeg mob kev noj qab haus huv. Txawm li cas los xij, thaum siv tsis zoo, kev tshaj xov xwm hauv social media muaj qhov tsis zoo xws li kev ua txhaum ntawm cov neeg mob tsis pub leej twg paub thiab tsis pub leej twg paub thiab tuaj yeem ua rau muaj kev cuam tshuam loj heev
Dab tsi yog qhov zoo sib xws thiab qhov txawv ntawm relays thiab PLC yog dab tsi?
Relays yog electro-mechanical keyboards uas muaj coil thiab ob hom kev sib cuag uas tsis yog NO & NC. Tab sis Programmable Logic Controller, PLC yog lub khoos phis tawj me uas tuaj yeem txiav txim siab raws li qhov kev zov me nyuam thiab nws cov tswv yim & tso tawm