Koj puas tuaj yeem pivot hauv SQL?
Koj puas tuaj yeem pivot hauv SQL?

Video: Koj puas tuaj yeem pivot hauv SQL?

Video: Koj puas tuaj yeem pivot hauv SQL?
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Cov SQL ntawv Server (Kev hloov pauv- SQL ntawv ) PIVOT clause tso cai koj los sau ib tug hla-tabulation. Qhov no txhais tau tias koj ua tau aggregate koj cov txiaj ntsig thiab tig kab rau hauv kab.

Hais txog qhov no, pivot hauv SQL Server nrog piv txwv li cas?

SQL Server PIVOT tus neeg teb xov tooj rotates lub rooj-valued qhia. Nws hloov cov nqi tshwj xeeb hauv ib kem mus rau ntau kab hauv cov zis thiab ua cov kev sib sau ua ke ntawm txhua qhov seem seem. Thib ob, tsim qhov tshwm sim ib ntus los ntawm kev siv lub rooj sib tham lossis cov lus qhia sib tham (CTE) Thib peb, siv lub PIVOT tus neeg ua haujlwm.

Tsis tas li ntawd, pivot hauv SQL yog dab tsi? SQL PIVOT thiab UNPIVOT yog ob tus neeg ua haujlwm sib raug zoo uas siv los hloov cov lus qhia rau lwm tus. PIVOT yog siv thaum peb xav hloov cov ntaub ntawv los ntawm kab theem mus rau kab ke thiab UNPIVOT yog siv thaum peb xav hloov cov ntaub ntawv los ntawm kab theem mus rau kab theem.

Kuj paub, koj siv pivot thiab Unpivot hauv SQL li cas?

Cov PIVOT nqe lus yog siv los hloov cov kab lus rau hauv kab, thaum lub UNPIVOT tus neeg teb xov tooj hloov cov kab rov qab mus rau kab. Rov qab a PIVOT nqe lus hais txog tus txheej txheem ntawm kev thov cov UNPIVOT tus neeg teb xov tooj mus rau qhov twb PIVOTED dataset thiaj li yuav rov qab tau cov ntaub ntawv qub.

dynamic query yog dab tsi?

Cov lus nug dynamic xa mus rau lus nug uas yog tsim dynamically los ntawm Drupal es tsis yog muab raws li qhov tseeb nug txoj hlua. Tag nrho Insert, Update, Rho tawm, thiab Merge lus nug yuav tsum yog dynamic . Xaiv lus nug tej zaum yuav yog static los yog dynamic . Yog li ntawd, " dynamic lus nug "feem ntau yog hais txog a dynamic Xaiv nug.

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