SQL datetime set to midnight

Hi all

There are two elements to this question, but both simple answers.

1)  I have a table of datetimes for which the time component is whenever the record was created.  I need a SQL update query to set them all to midnight.

ie to convert 01/05/2009 21:23:22 to 01/05/2009 00:00:00

2) I am running a query which gets all matching records between @fromdate and @todate.  Where these are string parameters from user input.

How can I add a time to the parameter like this:

@fromdate must be @fromdate 00:00:00  (ie midnight)

@todate must be @todate 23:59:59 (ie last second of the day).

LVL 1
Ross EdwardsTechnical DirectorAsked:
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Raja Jegan RSQL Server DBA & Architect, EE Solution GuideCommented:
1. This should help

update ur_table
set ur_datetime_col = dateadd(d, datediff(d, 0, ur_datetime_col), 0)

2. This should help

select * from ur_table
where ur_datetime_col between ur_datetime_col = dateadd(d, datediff(d, 0, ur_datetime_col), 0)
and ur_datetime_col = dateadd( ms, -2 , dateadd(d, datediff(d, 0, ur_datetime_col), 1))
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Aneesh RetnakaranDatabase AdministratorCommented:
UPDATE urTable
SET urDateColumn = CONVERT(Varchar, urdatecolumn, 112)
WHERE urDateColumn >=@fromdate AND urDateColumn < @todate -1

UPDATE urTable
SET urDateColumn = DATEADD(second, -1, @Todate )
WHERE urDateColumn >= @todate -1  AND urDateColumn < @Todate
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Raja Jegan RSQL Server DBA & Architect, EE Solution GuideCommented:
Minor mistake for 2:

select * from ur_table
where ur_datetime_col between dateadd(d, datediff(d, 0, ur_datetime_col), 0)
and dateadd( ms, -2 , dateadd(d, datediff(d, 0, ur_datetime_col), 1))
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Raja Jegan RSQL Server DBA & Architect, EE Solution GuideCommented:
For 2, if you want it for the current day, then below should help

select * from ur_table
where ur_datetime_col between dateadd(d, datediff(d, 0, getdate()), 0)
and dateadd( ms, -2 , dateadd(d, datediff(d, 0, getdate()), 1))

or Otherwise subtract the days from getdate()
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Ross EdwardsTechnical DirectorAuthor Commented:
Many thanks this worked!
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