I am trying to add some hours in SQL SERVER using DATEADD function. But when I try this,
SELECT DATEADD(Hour, 0.5, GETDATE())
It is not adding 0.5 hour. How to solve this?
You can't. It's well describer on documentation: DATEADD (Transact-SQL)
number
Is an expression that can be resolved to an int that is added
to a datepart of date. User-defined variables are valid.
If you specify a value with a decimal fraction, the fraction is truncated and
not rounded.
UPDATE
You could try that:
SELECT DATEADD(Second, 0.5 * 60 * 60, GETDATE())
Of course - you can change DATEPART and multiplier to get desired precision.
You can't add parts of hours, just full hours. Use minute for half an hour
SELECT DATEADD(minute, 30, GETDATE())
I have found another approach to this where adding a number to the date instead of using the function works for fractions. For example:
GETDATE() + n
where n is the number of days. For 1 half hour, you can use:
GETDATE() + 0.5/24
I have a column that stores data in datetime format. I want to check for all instances where the time part of this column is not equal to 00:00:00:000 - the date does not matter.
Basically, if time() was a function, something like this:
SELECT *
FROM progen.DY
WHERE TIME(DY_DATE) <> '00:00:00:000'
How do I go about doing this?
You only need a minor tweak on what you already have.
SELECT *
FROM progen.DY
WHERE TIME(DY_DATE) <> '00:00:00:000'
Use CONVERT to change your DATETIME to a TIME.
SELECT *
FROM progen.DY
WHERE CONVERT(TIME, DY_DATE) <> '00:00:00:000'
Another way is to convert it to different datatype, eg
SELECT *
FROM progen.DY
WHERE CAST(DY_DATE as float) - CAST(DY_DATE as int) > 0
SQLFiddle Demo
I do this all the time when trying to see if a table's column should be turned into a date instead of a datetime, which is really the answer.
select *
from progen.dy
where cast(dy_date as Date) <> dy_date
the cast removes the time and datetime has higher precedence, so when compared, if the are unequal then it has a time value. Same thing could be done with a cast to time, with a bit of different syntax.
Use DATEDIFF and DATEADD to instead get the date part of the datetime. Compare the column against the date only, and it will return those rows that have a non-zero time.
The way this works is that we first calculate the difference (in days) between the epoch and the value. We add that number to the epoch to create a new datetime. Since the result of DATEDIFF is an integer, any time component gets rounded off.
SELECT *
FROM Table
WHERE DateColumn <> DATEADD(d, DATEDIFF(d, 0, DateColumn), 0)
The time function could then be implemented by the following, not that I recommend it for this specific scenario:
SELECT DATEDIFF(minute, DATEADD(d, DATEDIFF(d, 0, DateColumn), 0), DateColumn) as MinutesIntoDay,
-- or, if you require higher precision
DATEDIFF(second, DATEADD(d, DATEDIFF(d, 0, DateColumn), 0), DateColumn) as MinutesIntoDay
FROM Table
Edit: As mentioned in other answers, you can cast to DATE to achieve the same effect as DATEADD(d, DATEDIFF(d, 0, DateColumn), 0), which cleans up nicely. However, DATE was only added in SQL Server 2008, whereas the formula has compatibility back to at least SQL 2000. So if you need the backwards compatibility or are dealing with SQL CE, casting to DATE is unavailable.
SELECT *
FROM progen.DY
WHERE CONVERT(TIME, DY_DATE - CONVERT(DATE, DY_DATE)) > '00:00'
i have a bigint field in Microsoft SQL Server 2008R2 filled with ticks (A single tick represents one hundred nanoseconds or one ten-millionth of a second. There are 10,000 ticks in a millisecond.)
http://msdn.microsoft.com/en-us/library/system.datetime.ticks.aspx
and i need to convert the sum of all records to Days:Hours:Minutes:Seconds:Milliseconds.
it works for a single record:
SELECT CONVERT(TIME, DATEADD(ms, duration/10000, 0)) FROM tblMediaFileProperties WHERE FileId = '6C0A849D-95B4-4755-A923-B9DD8F1AF23E'
but if a sum it up to all records using:
SELECT CONVERT(TIME, DATEADD(ms, SUM(duration/10000), 0)) FROM tblMediaFileProperties
i get a:
Arithmetic overflow error converting expression to data type int.
i know the overflow comes from the CONVERT to Data Type TIME Function...
help's appreciated, thanks!
It's too big for DATEADD which only accepts an int.
Break it into two parts: seconds, then milliseconds.
SELECT CONVERT(TIME,
DATEADD(ms, SUM(duration/10000 % 1000),
DATEADD(ss, SUM(duration/10000000), 0)))
FROM tblMediaFileProperties
And if your total duration goes above 1 day, you can use this to get the days and hr:min:sec:ms separately. It's a matter of cast and string concat if you actually want the result in textual form.
declare #duration bigint
set #duration = 1230000000
SELECT #duration/10000/1000/60/60/24 DAYS,
CONVERT(TIME,
DATEADD(ms, SUM(#duration/10000 % 1000),
DATEADD(ss, SUM(#duration/10000000), 0))) HR_MIN_SEC
Does anyone know how to get the datdiff in full days between 2 days.
Im currentlly using
datediff(day,createddate,dateserved)
But need it to return how many full days
i.e
Created = 1/7/2010 2100
dateserved = 2/7/2010 2000
currently the datediff would show 1 day but i need it to show 0 until dateserved passes 2100
Any ideas
Sp
SELECT FLOOR(CAST(dateserved AS FLOAT) - CAST( createddate AS FLOAT))
Also the following seems to work and be more concise but may need some testing
SELECT FLOOR(CAST(dateserved-createddate AS FLOAT))
#Ian Jacobs got it in first, but here's how I'd do it in T-SQL. Assuming you're only concerned with hours:
DECLARE
#From datetime
,#Thru datetime
SET #From = 'Jan 1, 2010 21:00'
SET #Thru = 'Jan 3, 2010 20:00' -- 2/7/2010 2000
print datediff(dd, #From, #Thru)
print datediff(hh, #From, #Thru)
PRINT datediff(hh, #From, #Thru) / 24
...that is, calculate the hours difference between your datetimes, divide by 24, and truncate the decimal value. SQL appears to truncate, but if you're paranoid, use
print datediff(hh, #From, #Thru) / 24.0
PRINT floor(datediff(hh, #From, #Thru) / 24.0)
to ensure proper truncation. If you need precision down to the minute, second, or millisecond, add bit more arithmatic.
What you can do is go with the smallest possible resolution in the DATEDIFF() function you can feasibly get away with (minutes,seconds, whatever). Then to math to convert that to a day representations.
I'm basically proposing:
Floor(DATEDIFF(mi, createddate, dateserved)/60/24);
You could use:
DATEDIFF(dy, created_date, date_served) -
CASE
WHEN CAST(created_date AS TIME) > CAST(date_served AS TIME) THEN 1
ELSE 0
END
I originally proposed trying to use division, but when you get down to milliseconds you can quickly hit arithmetic overflows.
I'm trying to compare time in a datetime field in a SQL query, but I don't know if it's right. I don't want to compare the date part, just the time part.
I'm doing this:
SELECT timeEvent
FROM tbEvents
WHERE convert(datetime, startHour, 8) >= convert(datetime, #startHour, 8)
Is it correct?
I'm asking this because I need to know if 08:00:00 is less or greater than 07:30:00 and I don't want to compare the date, just the time part.
Thanks!
Your compare will work, but it will be slow because the dates are converted to a string for each row. To efficiently compare two time parts, try:
declare #first datetime
set #first = '2009-04-30 19:47:16.123'
declare #second datetime
set #second = '2009-04-10 19:47:16.123'
select (cast(#first as float) - floor(cast(#first as float))) -
(cast(#second as float) - floor(cast(#second as float)))
as Difference
Long explanation: a date in SQL server is stored as a floating point number. The digits before the decimal point represent the date. The digits after the decimal point represent the time.
So here's an example date:
declare #mydate datetime
set #mydate = '2009-04-30 19:47:16.123'
Let's convert it to a float:
declare #myfloat float
set #myfloat = cast(#mydate as float)
select #myfloat
-- Shows 39931,8244921682
Now take the part after the comma character, i.e. the time:
set #myfloat = #myfloat - floor(#myfloat)
select #myfloat
-- Shows 0,824492168212601
Convert it back to a datetime:
declare #mytime datetime
set #mytime = convert(datetime,#myfloat)
select #mytime
-- Shows 1900-01-01 19:47:16.123
The 1900-01-01 is just the "zero" date; you can display the time part with convert, specifying for example format 108, which is just the time:
select convert(varchar(32),#mytime,108)
-- Shows 19:47:16
Conversions between datetime and float are pretty fast, because they're basically stored in the same way.
convert(varchar(5), thedate, 108) between #leftTime and #rightTime
Explanation:
if you have varchar(5) you will obtain HH:mm
if you have varchar(8) you obtain HH:mm ss
108 obtains only the time from the SQL date
#leftTime and #rightTime are two variables to compare
If you're using SQL Server 2008, you can do this:
WHERE CONVERT(time(0), startHour) >= CONVERT(time(0), #startTime)
Here's a full test:
DECLARE #tbEvents TABLE (
timeEvent int IDENTITY,
startHour datetime
)
INSERT INTO #tbEvents (startHour) SELECT DATEADD(hh, 0, GETDATE())
INSERT INTO #tbEvents (startHour) SELECT DATEADD(hh, 1, GETDATE())
INSERT INTO #tbEvents (startHour) SELECT DATEADD(hh, 2, GETDATE())
INSERT INTO #tbEvents (startHour) SELECT DATEADD(hh, 3, GETDATE())
INSERT INTO #tbEvents (startHour) SELECT DATEADD(hh, 4, GETDATE())
INSERT INTO #tbEvents (startHour) SELECT DATEADD(hh, 5, GETDATE())
--SELECT * FROM #tbEvents
DECLARE #startTime datetime
SET #startTime = DATEADD(mi, 65, GETDATE())
SELECT
timeEvent,
CONVERT(time(0), startHour) AS 'startHour',
CONVERT(time(0), #startTime) AS '#startTime'
FROM #tbEvents
WHERE CONVERT(time(0), startHour) >= CONVERT(time(0), #startTime)
Just change convert datetime to time that should do the trick:
SELECT timeEvent
FROM tbEvents
WHERE convert(time, startHour) >= convert(time, #startHour)
if (cast('2012-06-20 23:49:14.363' as time) between
cast('2012-06-20 23:49:14.363' as time) and
cast('2012-06-20 23:49:14.363' as time))
One (possibly small) issue I have noted with the solutions so far is that they all seem to require a function call to process the comparison. This means that the query engine will need to do a full table scan to seek the rows you are after - and be unable to use an index. If the table is not going to get particularly large, this probably won't have any adverse affects (and you can happily ignore this answer).
If, on the other hand, the table could get quite large, the performance of the query could suffer.
I know you stated that you do not wish to compare the date part - but is there an actual date being stored in the datetime column, or are you using it to store only the time? If the latter, you can use a simple comparison operator, and this will reduce both CPU usage, and allow the query engine to use statistics and indexes (if present) to optimise the query.
If, however, the datetime column is being used to store both the date and time of the event, this obviously won't work. In this case if you can modify the app and the table structure, separate the date and time into two separate datetime columns, or create a indexed view that selects all the (relevant) columns of the source table, and a further column that contains the time element you wish to search for (use any of the previous answers to compute this) - and alter the app to query the view instead.
Using float does not work.
DECLARE #t1 datetime, #t2 datetime
SELECT #t1 = '19000101 23:55:00', #t2 = '20001102 23:55:00'
SELECT CAST(#t1 as float) - floor(CAST(#t1 as float)), CAST(#t2 as float) - floor(CAST(#t2 as float))
You'll see that the values are not the same (SQL Server 2005). I wanted to use this method to check for times around midnight (the full method has more detail) in which I was comparing the current time for being between 23:55:00 and 00:05:00.
Adding to the other answers:
you can create a function for trimming the date from a datetime
CREATE FUNCTION dbo.f_trimdate (#dat datetime) RETURNS DATETIME AS BEGIN
RETURN CONVERT(DATETIME, CONVERT(FLOAT, #dat) - CONVERT(INT, #dat))
END
So this:
DECLARE #dat DATETIME
SELECT #dat = '20080201 02:25:46.000'
SELECT dbo.f_trimdate(#dat)
Will return
1900-01-01 02:25:46.000
Use Datepart function: DATEPART(datepart, date)
E.g#
SELECT DatePart(#YourVar, hh)*60) +
DatePart(#YourVar, mi)*60)
This will give you total time of day in minutes allowing you to compare more easily.
You can use DateDiff if your dates are going to be the same, otherwise you'll need to strip out the date as above
You can create a two variables of datetime, and set only hour of date that your need to compare.
declare #date1 datetime;
declare #date2 datetime;
select #date1 = CONVERT(varchar(20),CONVERT(datetime, '2011-02-11 08:00:00'), 114)
select #date2 = CONVERT(varchar(20),GETDATE(), 114)
The date will be "1900-01-01" you can compare it
if #date1 <= #date2
print '#date1 less then #date2'
else
print '#date1 more then #date2'
SELECT timeEvent
FROM tbEvents
WHERE CONVERT(VARCHAR,startHour,108) >= '01:01:01'
This tells SQL Server to convert the current date/time into a varchar using style 108, which is "hh:mm:ss". You can also replace '01:01:01' which another convert if necessary.
I believe you want to use DATEPART('hour', datetime).
Reference is here:
http://msdn.microsoft.com/en-us/library/ms174420.aspx
I don't love relying on storage internals (that datetime is a float with whole number = day and fractional = time), but I do the same thing as the answer Jhonny D. Cano. This is the way all of the db devs I know do it. Definitely do not convert to string. If you must avoid processing as float/int, then the best option is to pull out hour/minute/second/milliseconds with DatePart()
I am assuming your startHour column and #startHour variable are both DATETIME; In that case, you should be converting to a string:
SELECT timeEvent
FROM tbEvents
WHERE convert(VARCHAR(8), startHour, 8) >= convert(VARCHAR(8), #startHour, 8)
below query gives you time of the date
select DateAdd(day,-DateDiff(day,0,YourDateTime),YourDateTime) As NewTime from Table
#ronmurp raises a valid concern - the cast/floor approach returns different values for the same time. Along the lines of the answer by #littlechris and for a more general solution that solves for times that have a minute, seconds, milliseconds component, you could use this function to count the number of milliseconds from the start of the day.
Create Function [dbo].[MsFromStartOfDay] ( #DateTime datetime )
Returns int
As
Begin
Return (
( Datepart( ms , #DateTime ) ) +
( Datepart( ss , #DateTime ) * 1000 ) +
( Datepart( mi , #DateTime ) * 1000 * 60 ) +
( Datepart( hh , #DateTime ) * 1000 * 60 * 60 )
)
End
I've verified that it returns the same int for two different dates with the same time
declare #first datetime
set #first = '1900-01-01 23:59:39.090'
declare #second datetime
set #second = '2000-11-02 23:56:39.090'
Select dbo.MsFromStartOfDay( #first )
Select dbo.MsFromStartOfDay( #second )
This solution doesn't always return the int you would expect. For example, try the below in SQL 2005, it returns an int ending in '557' instead of '556'.
set #first = '1900-01-01 23:59:39.556'
set #second = '2000-11-02 23:56:39.556'
I think this has to do with the nature of DateTime stored as float. You can still compare the two number, though. And when I used this approach on a "real" dataset of DateTime captured in .NET using DateTime.Now() and stored in SQL, I found that the calculations were accurate.
TL;DR
Separate the time value from the date value if you want to use indexes in your search (you probably should, for performance). You can: (1) use function-based indexes or (2) create a new column for time only, index this column and use it in you SELECT clause.
Keep in mind you will lose any index performance boost if you use functions in a SQL's WHERE clause, the engine has to do a scan search. Just run your query with EXPLAIN SELECT... to confirm this. This happens because the engine has to process EVERY value in the field for EACH comparison, and the converted value is not indexed.
Most answers say to use float(), convert(), cast(), addtime(), etc.. Again, your database won't use indexes if you do this. For small tables that may be OK.
It is OK to use functions in WHERE params though (where field = func(value)), because you won't be changing EACH field's value in the table.
In case you want to keep use of indexes, you can create a function-based index for the time value. The proper way to do this (and support for it) may depend on your database engine. Another option is adding a column to store only the time value and index this column, but try the former approach first.
Edit 06-02
Do some performance tests before updating your database to have a new time column or whatever to make use of indexes. In my tests, I found out the performance boost was minimal (when I could see some improvement) and wouldn't be worth the trouble and overhead of adding a new index.