Video: Dab tsi yog qhov loj me ntawm cov ntaub ntawv hauv MS Access?
2024 Tus sau: Lynn Donovan | [email protected]. Kawg hloov kho: 2023-12-15 23:47
Qhia meej txog Microsoft Access Data Type
| Kev teeb tsa | Kev piav qhia | Cia Loj |
|---|---|---|
| Byte | Khaws cov lej ntawm 0 txog 255 (tsis muaj feem). | 1 byte ib |
| Tus lej | Khaws cov lej ntawm -32, 768 txog 32, 767 (nofractions). | 2 bytes |
| Ntev Integer | (Default) Khaws cov lej ntawm -2, 147, 483, 648 txog 2, 147, 483, 647 (tsis muaj feem). | 4 bytes |
Nyob rau hauv no hais txog, dab tsi yog lub neej ntawd cov ntaub ntawv nyob rau hauv kev nkag tau?
Tus naj npawb hom ntaub ntawv Yog li los ntawm ua ntej , Tus lej teb tuaj yeem muaj tus lej tag nrho.
Ib yam li ntawd, muaj pes tsawg cov ntaub ntawv hom Access muaj? Basic Hom Nco ntsoov tias muaj qhov sib cais hom ntaub ntawv nyiaj txiag. Yog thiab Tsis muaj qhov tseem ceeb thiab cov teb uas tsuas muaj ib qho ntawm ob qhov tseem ceeb. Hnub tim thiab Lub Sijhawm qhov tseem ceeb rau xyoo 100 txog 9999.
Tom qab ntawd, ib tus tuaj yeem nug, qhov loj me hauv MS Access yog dab tsi?
Koj tuaj yeem sau tus nqi ntawm 1 txog 255. Cov lej no qhia txog tus lej siab tshaj plaws uas txhua tus nqi tuaj yeem muaj. Rau cov ntawv loj teb , siv Memo cov ntaub ntawv hom (LongText yog siv Nkag mus 2016). Cov Teb Loj khoom yog qhov siab tshaj plaws teb tus nqi qhov loj.
Qhov luaj li cas nyob rau hauv ib lub database yog dab tsi?
A database / cov ntaub ntawv nkag lub sijhawm. Tag nrho cov ntaub ntawv nkag teb muaj qhov siab tshaj plaws qhov loj . Piv txwv li asingle kab input teb feem ntau muaj 255 tus cim txwv, thaum lub thawv ntawv txwv yuav yog 65,000 tus cim.
Pom zoo:
Dab tsi yog qhov sib txawv ntawm pab pawg cov ntaub ntawv thiab cov ntaub ntawv tsis yog pawg?
Ob leeg yog cov ntaub ntawv muaj txiaj ntsig ntawm cov ntaub ntawv tab sis qhov sib txawv ntawm lawv yog cov ntaub ntawv tsis muaj ntaub ntawv yog rawdata. Qhov no txhais tau hais tias nws nyuam qhuav tau sau tab sis tsis txheeb rau hauv ib pawg lossis cov chav kawm. Ntawm qhov tod tes, groupeddata yog cov ntaub ntawv uas tau teeb tsa ua pawg los ntawm cov ntaub ntawv nyoos
Dab tsi yog kev noj cov ntaub ntawv hauv cov ntaub ntawv loj?
Cov ntaub ntawv ingestion yog tus txheej txheem ntawm tau txais thiab import cov ntaub ntawv rau tam sim ntawd siv los yog cia nyob rau hauv ib tug database. Txhawm rau noj ib yam dab tsi yog 'coj ib yam dab tsi los yog nqus ib yam dab tsi.' Cov ntaub ntawv tuaj yeem xa tawm hauv lub sijhawm tiag tiag lossis noj hauv cov khoom siv
Dab tsi yog qhov sib txawv ntawm cov ntaub ntawv hauv cov ntaub ntawv mining?
Cia peb tham txog yam ntaub ntawv twg tuaj yeem raug mined: Cov ntaub ntawv tiaj tus. Relational Databases. DataWarehouse. Transactional Databases. Multimedia Databases. Spatial Databases. Lub Sijhawm Series Databases. World Wide Web (WWW)
Vim li cas kem taw qhia cov ntaub ntawv khaws cia ua cov ntaub ntawv nkag ntawm disks sai dua li kab qhia cov ntaub ntawv khaws cia?
Kem oriented databases (aka columnar databases) yog qhov tsim nyog rau kev ntsuas kev ua haujlwm ntau dua vim tias cov ntaub ntawv hom ntawv (kem hom) qiv nws tus kheej kom nrawm dua cov lus nug ua - scans, aggregation thiab lwm yam. Ntawm qhov tod tes, kab oriented databases khaws ib kab (thiab tag nrho nws. kab) contiguously
Dab tsi yog cov teeb meem ntawm kev tswj cov ntaub ntawv hauv cov ntaub ntawv ib txwm muaj?
Nyob rau tib lub sijhawm, qhov kev tswj hwm cov ntaub ntawv ib puag ncig tsim teeb meem xws li cov ntaub ntawv rov ua dua thiab tsis sib xws, cov kev pab cuam-cov ntaub ntawv dependence, inflexibility, tsis muaj kev ruaj ntseg, thiab tsis muaj cov ntaub ntawv sib qhia thiab muaj