Video: Datediff ua dab tsi hauv SQL?
2024 Tus sau: Lynn Donovan | [email protected]. Kawg hloov kho: 2023-12-15 23:47
Hauv SQL ntawv Server, koj tuaj yeem siv T- SQL DATEDIFF () ua haujlwm kom rov qab qhov sib txawv ntawm ob hnub / sijhawm. Nws ua haujlwm ntawm txhua qhov kev qhia uas tuaj yeem daws tau rau lub sijhawm, hnub tim, lub sijhawm me me, hnub tim, hnub tim 2, lossis hnub tim offset tus nqi.
Tsis tas li ntawd, datediff ua haujlwm li cas hauv SQL?
Cov DATEDIFF () muaj nuj nqi xa rov qab tus nqi ntawm tus lej qhia qhov sib txawv ntawm start_date thiab end_date, nrog rau chav tsev teev los ntawm date_part. Cov DATEDIFF () kev ua haujlwm rov qab ua yuam kev yog tias qhov tshwm sim yog tawm ntawm ntau yam rau integer (-2, 147, 483, 648 txog +2, 147, 483, 647).
Tsis tas li ntawd, koj puas tuaj yeem rho tawm hnub hauv SQL? Yuav ua li cas rho tawm hnub hauv SQL Server – Querychat. SQL ntawv Server tsis txhawb tus neeg teb xov tooj rho tawm tab sis muaj cov npe ntev ntawm cov haujlwm uas tso cai rau peb ua haujlwm nrog hnub hom teb xws li DATEADD, DATEDIFF, DATENAME, DATEPART, HNUB, GETDATE, MONTH, YEAR, thiab lwm yam.
Yog li ntawd, koj siv datediff li cas?
Txhawm rau xam cov hnub ntawm hnub tim 1 thiab hnub tim 2, koj tuaj yeem ua tau siv Hnub ntawm lub xyoo ("y") lossis Hnub ("d"). Thaum lub sij hawm yog hnub Monday ("w"), Hnub timDiff rov qab tus naj npawb ntawm lub lis piam ntawm ob hnub. Yog tias hnub tim 1 poob rau hnub Monday, Hnub timDiff suav cov hnub Monday txog hnub tim 2.
Kuv tuaj yeem tau txais hnub ntawm ob hnub hauv SQL Server li cas?
PRINT DATEDIFF(HNUB, '1/1/2011', '3/1/2011') yuav muab koj li cas tom qab. Qhov no muab pes tsawg zaus ntawm ib tag hmo ciam teb hla nruab nrab tus ob hnub . Koj tuaj yeem txiav txim siab xav tau ntxiv ib qho rau qhov no yog tias koj suav nrog ob qho tib si hnub tim hauv suav - lossis rho tawm ib qho yog tias koj tsis xav suav nrog hnub.
Pom zoo:
Dab tsi yog kev koom nrog sab hauv hauv SQL?
Inner Join hauv SQL yog dab tsi? INNER JOIN xaiv txhua kab los ntawm ob lub rooj koom nrog tsuav yog tias muaj qhov sib tw ntawm cov kab. Ib qho SQL INNER JOIN yog tib yam li JOIN clause, sib txuas cov kab los ntawm ob lossis ntau lub rooj
Dab tsi yog qhov txawv ntawm qhov sib txawv hauv zos thiab thoob ntiaj teb hauv SQL Server?
Qhov sib txawv hauv zos tau tshaj tawm hauv ib qho kev ua haujlwm whereas Ntiaj teb hloov pauv tau tshaj tawm sab nraum lub luag haujlwm. Cov kev hloov hauv zos tau tsim thaum lub luag haujlwm tau pib ua tiav thiab ploj thaum lub luag haujlwm xaus, ntawm qhov tod tes, Ntiaj teb hloov pauv yog tsim raws li kev tua pib thiab ploj thaum qhov kev pab cuam xaus
Dab tsi yog txoj hauv kev virtual thiab txoj hauv lub cev hauv asp net?
Ua ntej tshaj, cia peb tau txais cov ntsiab lus ntawm ob qho tib si. Txoj kev lub cev - Qhov no yog txoj hauv kev tiag tiag cov ntaub ntawv nyob ntawm IIS. Txoj kev Virtual - Qhov no yog txoj hauv kev kom nkag mus rau cov ntaub ntawv uas tau taw qhia los ntawm sab nraud ntawm IIS daim ntawv thov folder
Dab tsi yog datediff muaj nuj nqi hauv SQL?
DATEDIFF() muaj nuj nqi xa rov qab tus nqi ntawm tus lej qhia qhov sib txawv ntawm start_date thiab end_date, nrog rau chav tsev teev los ntawm date_part. Lub DATEDIFF() muaj nuj nqi rov qab qhov yuam kev yog tias qhov tshwm sim tawm ntawm qhov ntau ntawm cov lej (-2,147,483,648 txog +2,147,483,647)
Dab tsi yog qhov tsis muaj dab tsi hauv Java?
Pej xeem txhais tau hais tias txoj kev pom thiab tuaj yeem raug hu los ntawm lwm yam khoom ntawm lwm hom. Lwm cov kev xaiv yog tus kheej, tiv thaiv, pob thiab pob-private.Qhov no txhais tau hais tias koj tuaj yeem hu rau txoj kev zoo li qub yam tsis muaj kev tsim anobject ntawm chav kawm. void txhais tau hais tias txoj kev tsis muaj nqi