RE: Understanding CAST(INT AS DATETIME)

ChrisM@Work

SSC Guru

Points: 186127

May 21, 2015 at 3:39 am

#1799584

Food for thought:

SELECT DATEDIFF(millisecond,'20150521','20150522') --86400000 ms in a day

SELECT

RightNow, RightNowNumeric, RightNowDecimalPart, RightNowIntegerPart,

ReconstructedDate = DATEADD(day,RightNowIntegerPart,0),

ReconstructedDateTime = DATEADD(millisecond,86400000*RightNowDecimalPart,DATEADD(day,RightNowIntegerPart,0))

FROM (

SELECT

RightNow,

RightNowNumeric = CAST(RightNow AS NUMERIC(18,12)),

RightNowDecimalPart = CAST(RightNow AS NUMERIC(18,12))%1,

RightNowIntegerPart = CAST(CAST(RightNow AS NUMERIC(18,12)) - CAST(RightNow AS NUMERIC(18,12))%1 AS INT)

FROM (

SELECT RightNow = GETDATE()) d

) e

^{“Write the query the simplest way. If through testing it becomes clear that the performance is inadequate, consider alternative query forms.” - Gail Shaw}

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