Cov txheej txheem:

Cov pivot puas tuaj yeem siv yam tsis muaj kev sib sau ua ke?
Cov pivot puas tuaj yeem siv yam tsis muaj kev sib sau ua ke?

Video: Cov pivot puas tuaj yeem siv yam tsis muaj kev sib sau ua ke?

Video: Cov pivot puas tuaj yeem siv yam tsis muaj kev sib sau ua ke?
Video: Nkauj ntseeg tawm tshiab 2023 || CAS PEB COV NTSEEG || nkauj tshawb zog [official MV] Txawj plaub 2024, Kaum ib hlis
Anonim

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

  1. SELECT *
  2. Los ntawm.
  3. (
  4. SELECT StudentRegCode, ExamTypeCode, ObtainedMark NTAWM StudentSubjectMark.
  5. ) AS SourceTable.
  6. PIVOT.
  7. (MIN([ObtainedMark]) RAU [ExamTypeCode] IN([1], [3], [4])) AS PivotTable;

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