2024 Tus sau: Lynn Donovan | [email protected]. Kawg hloov kho: 2023-12-15 23:47
Apex yog ib hom ntawv zoo heev, yam khoom-oriented programming lus. Ib yam li lwm tus programming lus, Apex muaj ntau yam hom ntaub ntawv uas koj siv tau. 1). Keeb kwm Hom - Qhov no hom ntaub ntawv xws li String, Integer, Long, Ob, Decimal, ID, Boolean, Hnub, Hnub, Lub Sijhawm thiab Blob.
Ib yam li ntawd, tib neeg nug, pes tsawg hom ntaub ntawv muaj nyob hauv Salesforce?
Cov ntaub ntawv sib txawv hauv Salesforce Lub tsib cov ntaub ntawv sib txawv hauv API: ID. Txoj hlua. Boolean.
Tsis tas li ntawd, hom ntaub ntawv twg yog ID? Cov ntaub ntawv hom
| Hom ntaub ntawv | Cov ntaub ntawv tus nqi |
|---|---|
| NTEXT | Txog li 4000 bytes ib kab hauv UTF-8 cim encoding. Hom ntaub ntawv no sib npaug rau NCHAR thiab NVARCHAR2 cov ntaub ntawv hom hauv cov ntaub ntawv. |
| ID | Txog li 8 tus cim ib kab hauv cov cim database |
Ib yam li ntawd, koj tuaj yeem nug, cov ntaub ntawv sib txawv yog dab tsi?
Qee yam hom ntaub ntawv suav nrog integers, floating point tooj, cim, hlua, thiab arrays. Tej zaum lawv kuj yuav hais meej dua hom , xws li hnub tim, timestamps, boolean qhov tseem ceeb, thiab varchar ( sib txawv tus cwj pwm) formats.
Dab tsi yog qhov txawv txav hauv Salesforce?
Variable Scope Variables tuaj yeem txhais tau ntawm txhua qhov chaw hauv ib qho thaiv, thiab coj mus thaj tsam los ntawm qhov ntawd mus tom ntej. Sub-blocks tsis tuaj yeem rov txhais ib sib txawv lub npe uas twb tau siv nyob rau hauv ib tug niam txiv thaiv, tab sis parallel blocks yuav rov siv tau a sib txawv npe.
Pom zoo:
Dab tsi yog lub hom phiaj ntawm delimiters nyob rau hauv cov ntawv sau npe ob hom ntawv cov ntaub ntawv delimiters?
Cov ntaub ntawv delimited yog cov ntawv nyeem siv los khaws cov ntaub ntawv, uas txhua kab sawv cev rau ib phau ntawv, tuam txhab, lossis lwm yam, thiab txhua kab muaj cov teb sib cais los ntawm tus lej
Dab tsi yog daim teb uas muaj cov ntaub ntawv tshwj xeeb rau cov ntaub ntawv?
Kev teeb tsa thawj tus yuam sij Tus yuam sij tseem ceeb yog daim teb uas muaj cov ntaub ntawv tshwj xeeb rau txhua cov ntaub ntawv
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 qhov sib txawv ntawm cov qauv siv nyob rau hauv cov ntaub ntawv ntawm cov khoom oriented qauv?
Cov qauv tseem ceeb ntawm cov qauv uas siv rau hauv cov khoom siv yog: Siv cov qauv qauv, Cov qauv qauv (zoo li qub) cov qauv, Cov qauv coj tus cwj pwm (dynamic) khoom qauv
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