composing a SQL query with a date offset
I am trying to do this:
select * from table
where ChangingDate(this is 开发者_运维问答a column which has date and time) = today's date + 1
I am a learner of SQL, and I am bad at date formats. I appreciate if someone can help.
Thank you!
This will return tomorrow's data
WHERE ChangingDate > = dateadd(dd, datediff(dd, 0, getdate())+1, 0)
and ChangingDate < dateadd(dd, datediff(dd, 0, getdate())+2, 0)
This will return today's data
WHERE ChangingDate > = dateadd(dd, datediff(dd, 0, getdate())+0, 0)
and ChangingDate < dateadd(dd, datediff(dd, 0, getdate())+1, 0)
See also How Does Between Work With Dates In SQL Server?
There's a trick with datetimes in databases - you almost never want an = comparison, because as you saw they also include a time component. Instead, you want to know if it falls inside a range that includes the entire day. Sql Server 2008 has a new date
type that helps with this, but until you upgrade, do it like this:
WHERE (ChangingDate >= dateadd(dd,1, datediff(dd,0, getDate()))
AND ChangingDate < dateadd(dd,2, datediff(dd,0, getDate())))
You can do an equals comparison if you are certain that all the records have a 0-value (or other known value) for the time component in that column. What you don't want to do is truncate the column, because that means doing extra work per-record (slow) and will break your index (very slow).
select *
from MyTable
where DATEADD(dd, 0, DATEDIFF(dd, 0, ChangingDate)) = SELECT DATEADD(dd, 1, DATEDIFF(dd, 0, GETDATE()))
you may want to try something like
select * from table where columndate=GetDate() + 1
Sounds like you want the DATEPART function to find where the column date has the same year, month, day regardless of time of day:
SELECT * FROM Table
WHERE
DATEPART(Month, Date) = DATEPART(Month, @SomeDate)
AND DATEPART(Day, Date) = DATEPART(Day, @SomeDate)
AND DATEPART(Year, Date) = DATEPART(Year, @SomeDate)
Otherwise, you want to use DateAdd like the other posters.
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