Dab tsi yog DW hauv Datepart hauv SQL Server?
Dab tsi yog DW hauv Datepart hauv SQL Server?

Video: Dab tsi yog DW hauv Datepart hauv SQL Server?

Video: Dab tsi yog DW hauv Datepart hauv SQL Server?
Video: Ob zaj dab neeg By Nquab Tsab New Song 2023 2024, Kaum ib hlis
Anonim

tus DATE PART . Thaum hnub Sunday yog thawj hnub ntawm lub lim tiam rau lub SQL Server , DATE PART ( dw ua ,) yuav rov qab 1 thaum hnub yog hnub Sunday thiab 7 thaum hnub yog hnub Saturday. (Hauv Tebchaws Europe, qhov twg hnub Monday yog thawj hnub ntawm lub limtiam, DATE PART ( dw ua ,) yuav rov qab 1 thaum hnub yog hnub Monday thiab 7 thaum hnub yog hnub Sunday.)

Ib sab ntawm qhov no, qhov txawv ntawm Datepart () thiab Datename () hauv SQL Server yog dab tsi?

Rov qab ib txoj hlua cim uas sawv cev rau qhov teev tseg hnub tim ntawm hnub tim. Raws li lawv cov lus txhais, tsuas yog qhov sib txawv ntawm ob txoj haujlwm no yog hom rov qab: Hnub tim () xa ib tus lej. DATENAME() rov qab ib txoj hlua.

Ib yam li ntawd, ISO lub lim tiam hauv SQL yog dab tsi? iso_week datepart ISO 8601 suav ISO lub lim tiam - hnub system, tus lej system rau lub lis piam . Txhua lub lim tiam yog txuam nrog lub xyoo uas hnub Thursday tshwm sim. Piv txwv li, lub lim tiam 1 ntawm 2004 (2004W01) muaj hnub Monday, 29 Kaum Ob Hlis 2003 txog Hnub Sunday, 4 Lub Ib Hlis 2004.

Kuj kom paub, Datepart SQL yog dab tsi?

Hauv SQL ntawv Server, T- SQL DATEPART () muaj nuj nqi rov qab tus lej uas sawv cev rau qhov teev tseg hnub tim ntawm hnub tim. Piv txwv li, koj tuaj yeem dhau xyoo 2021-01-07 thiab muaj SQL ntawv Cov neeg rau zaub mov xa rov qab tsuas yog feem xyoo (2021). Koj tseem tuaj yeem rho tawm lub sijhawm.

@@ DateFirst yog dab tsi?

DateFirst yog ib hom ntawm lub limtiam hnub teeb tsa hauv SQL Server uas qhia txog qhov pib ntawm lub lim tiam. Koj tuaj yeem hloov kho hnub pib ntawm lub lim tiam nrog qhov teeb tsa no. Yog DateFirst = 7 ces hnub Sunday uas yog hnub xya ntawm lub lim tiam yog suav tias yog thawj hnub ntawm lub lim tiam.

Pom zoo: