Video: Cassandra puas tuaj yeem khaws JSON?
2024 Tus sau: Lynn Donovan | [email protected]. Kawg hloov kho: 2023-12-15 23:47
Cassandra muab kev txhawb nqa rau JSON . Koj ua tau , tau kawg, khaws JSON ntawv rau hauv Cassandra cov kab ntawv.
Yog li ntawd, dab tsi yog ib tsev neeg nyob hauv Cassandra?
A tsev neeg kem yog lub thawv rau kev txiav txim sau cov kab. Txhua kab, nyob rau hauv lem, yog ib tug txiav txim sau ntawm kab . Cov rooj sib txheeb txhais nkaus xwb kab thiab tus neeg siv sau rau hauv lub rooj nrog qhov tseem ceeb. Hauv Cassandra , ib lub rooj muaj kab , lossis tuaj yeem txhais tau tias yog super tsev neeg kem.
Tsis tas li ntawd, Cassandra puas muaj schema? Cassandra tuaj yeem xav tias yog qhov tseem ceeb-tus nqi database. Hauv qab lub hood thiab dhau ntawm nws Cassandra Lus nug (CQL) thiab schemas , nws yeej muaj tus yuam sij nrhiav rau txhua cov ntaub ntawv hauv daim ntawv ntawm tus yuam sij tseem ceeb. Tus username teb ua raws li thawj zaug thiab tsuas yog thawj tus yuam sij, uas nyob rau hauv Cassandra tus hais lus yog hu ua tus yuam sij muab faib.
Hais txog qhov no, Cassandra schema tsawg dua database?
Txij li thaum nws creation, Cassandra yog nto moo ua ib tug Schema - tsawg / schema - dawb database hauv nws tsev neeg kem. Hauv Cassandra , kab tuaj yeem tsim los ntawm koj lub siab nyiam hauv kab. Cassandra cov qauv ntaub ntawv kuj famously hu ua a schema - xaiv cov ntaub ntawv qauv.
Koj ntxiv cov ntaub ntawv hauv Cassandra li cas?
Ntxig Cov Ntaub Ntawv txib ' Ntxig rau hauv' sau cov ntaub ntawv hauv Cassandra kab hauv kab ntawv. Nws tsuas khaws cov kab ntawv uas tau muab los ntawm tus neeg siv. Koj yuav tsum tau qhia kom meej tsuas yog lub hauv paus tseem ceeb kem. Nws yuav tsis siv qhov chaw rau tsis muab tus nqi.
Pom zoo:
Peb puas tuaj yeem khaws cov ntaub ntawv sib txawv hauv ArrayList hauv C#?
Yog lawm, koj tuaj yeem khaws cov khoom sib txawv hauv ArrayList tab sis, zoo li pst tau hais, nws yog qhov mob rau lawv tom qab. Yog tias cov txiaj ntsig muaj feem cuam tshuam rau qee txoj hauv kev koj yuav zoo dua los sau cov chav kawm los tuav lawv
Koj puas tuaj yeem khaws cov khoom ntawm boogie board?
Boogie Board Thaum kawg tuaj yeem khaws cov duab. Lub Rooj Tswjhwm Saib Boogie tshiab yuav tsis tsuas yog txuag cov ntaub ntawv, tab sis tig lub Bluetooth-compatible device rau hauv lub vijtsam thib ob. Txhawm rau txuag cov ntaub ntawv, 9.7-nti ntaus ntawv los nrog lub built-in micro SD daim npav nyeem ntawv
Koj puas tuaj yeem hloov tus kws kho mob hauv Internet thiab khaws koj tus email chaw nyob?
A: Hmoov tsis zoo, thaum koj hloov cov neeg muab kev pabcuam, koj tsis tuaj yeem nqa koj email chaw nyob nrog koj. Tom qab ntawd, thaum koj tau teeb tsa koj tus lej email tshiab, koj tuaj yeem teeb tsa xa mus rau koj tus lej ISP qub email rau koj qhov chaw nyob email tshiab ua ntej koj kaw
Kuv tuaj yeem khaws ib qho khoom xa tuaj rau kuv yuam kev?
Koj puas tuaj yeem khaws cov pob khoom tsis raug xa tuaj rau koj lub tsev? Cov lus teb yog yog thiab tsis yog, raws li Cov Lus Qhia Pej Xeem. Cov khoom uas tuam txhab xa tuaj rau koj, tab sis koj tsis tau xaj yog hu ua 'cov khoom tsis tau thov'. Firmscan coj koj mus rau lub tsev hais plaub kom rov qab tau lawv cov khoom
JSON tuaj yeem khaws cov haujlwm?
Tsis muaj hom ntaub ntawv ua haujlwm hauv JSON. JSON txhawb nqa khoom, arrays, hlua, lej, booleans thiab null. Nws yog hom ntaub ntawv, tsis yog hom lus programming. Nws tsis muaj txiaj ntsig ntau rau nws los txhawb kev ua haujlwm