Cov txheej txheem:
Video: Cov pivot puas tuaj yeem siv yam tsis muaj kev sib sau ua ke?
2024 Tus sau: Lynn Donovan | [email protected]. Kawg hloov kho: 2023-12-15 23:47
Koj ua tau tsis tshem tawm aggregate muaj nuj nqi , mas koj ua tau tsim koj cov lus nug raws li koj xav tau. Static PIVOT nug.
Hauv qhov no, peb puas tuaj yeem siv Pivot yam tsis muaj kev sib sau ua ke?
Pivoting Tsis muaj kev sib sau . Cov PIVOT tus neeg teb xov tooj yog ib qho cuab yeej siv tau. Nws cia koj aggreg thiab tig cov ntaub ntawv li ntawd koj ua tau tsim lub ntsiab lus uas yog yooj yim nyeem. Txawm li cas los xij, muaj yog lub sij hawm thaum koj tej zaum tsis xav tau tag nrho cov ntaub ntawv thaum pivoting ib lub rooj.
Tsis tas li ntawd, dab tsi yog tag nrho cov haujlwm hauv SQL? Aggregate functions hauv SQL . Hauv kev tswj hwm database ib aggregate muaj nuj nqi yog a muaj nuj nqi qhov twg qhov tseem ceeb ntawm ntau kab yog pawg ua ke raws li cov tswv yim ntawm qee cov qauv los tsim ib qho txiaj ntsig ntawm ntau lub ntsiab lus tseem ceeb.
Cov lus nug tseem yog, peb puas tuaj yeem siv Pivot yam tsis muaj kev sib sau ua ke hauv Oracle?
Koj ib txwm xav tau siv ib aggregate muaj nuj nqi thaum pivoting . Txawm tias koj tsis xav tau tiag tiag kev sib sau , yog, thaum twg koj pom nyob rau hauv lub rooj yog dab tsi koj ' yuav tau txais nyob rau hauv lub result set, koj tseem yuav tau siv ib aggregate muaj nuj nqi . Yog muaj yuav tsuas yog ib qho nqi ntxiv rau txhua lub cell, ces koj siv tau MIN lub MAX.
Kuv Yuav Pivot li cas yam tsis muaj kev sib sau ua ke hauv SQL Server?
Siv PIVOT hauv SQL Server yam tsis muaj kev sib sau ua ke
- SELECT *
- Los ntawm.
- (
- SELECT StudentRegCode, ExamTypeCode, ObtainedMark NTAWM StudentSubjectMark.
- ) AS SourceTable.
- PIVOT.
- (MIN([ObtainedMark]) RAU [ExamTypeCode] IN([1], [3], [4])) AS PivotTable;
Pom zoo:
Koj puas tuaj yeem siv pab pawg tsis muaj kev sib sau?
Koj tuaj yeem siv GROUP BY clause yam tsis tas siv cov haujlwm sib sau ua ke. Cov lus nug nram qab no tau txais cov ntaub ntawv los ntawm lub rooj them nyiaj thiab pab pawg cov txiaj ntsig los ntawm tus neeg siv khoom id. Hauv qhov no, GROUP BY ua haujlwm zoo li DISTINCT clause uas tshem tawm cov kab sib npaug ntawm qhov tshwm sim
Kuv tuaj yeem rov qab tau SQL Server cov ntaub ntawv los ntawm kev hloov kho tsis raug yam tsis muaj thaub qab?
Cov kev daws teeb meem feem ntau yog: Rov qab kho cov ntaub ntawv thaub qab thiab siv nws hloov pauv cov ntaub ntawv qub. Nyob rau hauv rooj plaub uas muaj lwm yam kev hloov pauv tau tshwm sim tom qab UPDATE lossis koj tsis tuaj yeem tso cai rau cov ntaub ntawv tawm hauv offline: Rov qab cov ntaub ntawv thaub qab ntawm lub server sim. Siv SQL Server Management Studio Export cov ntaub ntawv wizard kom xa cov ntaub ntawv
Ib qho chaw tsis muaj zog puas tuaj yeem muaj qhov chaw tsis muaj zog?
Hom chaw tsis muaj zog muaj qee qhov yuam sij. Nco tseg- Lub koom haum tsis muaj zog ib txwm muaj kev koom tes tag nrho tab sis lub koomhaum muaj zog yuav tsis muaj tag nrho kev koom tes.Weak entity yog nyob ntawm qhov chaw muaj zog kom ntseeg tau tias muaj qhov tsis muaj zog. Zoo li lub koom haum muaj zog, qhov tsis muaj zog tsis muaj qhov tseem ceeb, Nws muaj feem cuam tshuam kev ntxub ntxaug
Cov chav kawm twg tuaj yeem muaj cov tswvcuab ua haujlwm yam tsis muaj kev siv?
Cov chav kawm twg tuaj yeem muaj cov tswv cuab ua haujlwm yam tsis muaj lawv qhov kev siv? Kev piav qhia: Cov chav kawm paub daws teeb meem tuaj yeem muaj cov tswv cuab ua haujlwm yam tsis muaj kev siv, qhov twg cov subclasses tau txais yuav tsum siv cov haujlwm ntawd
Koj puas tuaj yeem rov qab qhov sib txawv backup yam tsis muaj kev thaub qab tag nrho?
1 Teb. Nws tsis tuaj yeem ua qhov sib txawv ntawm qhov thaub qab ntawm cov ntaub ntawv yog tias tsis muaj kev thaub qab yav dhau los. Ib tug txawv backup yog raws li nyob rau hauv tsis ntev los no, yav tas los tag nrho cov ntaub ntawv backup. Ib tug txawv backup captures tsuas yog cov ntaub ntawv uas tau hloov txij li thaum uas tag nrho backup