Video: Dab tsi yog datediff muaj nuj nqi hauv SQL?
2024 Tus sau: Lynn Donovan | [email protected]. Kawg hloov kho: 2023-12-15 23:47
Cov DATEDIFF () muaj nuj nqi 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 () 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).
Yog li ntawd, datediff ua dab tsi hauv SQL?
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.
Ib sab saum toj no, kuv yuav pom qhov txawv ntawm ob hnub hauv SQL lus nug li cas? Yuav xam cov qhov sib txawv ntawm ob hnub nyob rau hauv tib kem, peb siv CreateDate kem ntawm lub rooj sau npe thiab siv lub DATEDIFF ua haujlwm ntawm kab ntawv ntawd. Rau nrhiav tus qhov sib txawv ntawm ob hnub nyob rau hauv tib kem, peb xav tau ob hnub los ntawm tib kem.
Khaws qhov no hauv kev txiav txim siab, koj siv lub datediff ua haujlwm 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. Nws suav hnub tim 2 tab sis tsis yog hnub tim 1.
Dab tsi yog datediff access?
Lub Microsoft Access DateDiff kev ua haujlwm rov qab qhov sib txawv ntawm ob hnub tseem ceeb, raws li lub sijhawm teev tseg.
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