TSQL strip date from datetime - sql

What is the best way to strip the date from a DATETIME so only time is left to do a comparison?
I know I can do the following:
CONVERT(DATETIME, CONVERT(VARCHAR(8), GETDATE(),8))
But this involves convert and characters. If I wanted to check whether a time (including minutes) was between two other times stored in DATETIME columns, is there an elegant way to do this without having to rely on converting to character strings?


If you're using SQL 2008
SELECT CAST(GETDATE() AS TIME)


Try the TimeOnly function from Essential SQL Server Date, Time, and DateTime Functions:
create function TimeOnly(#DateTime DateTime)
returns datetime
as
begin
return dateadd(day, -datediff(day, 0, #datetime), #datetime)
end
go
Or simply cast the DateTime as Time in SQL Server 2008:
declare #time as time
set #time = cast(dateTimeVal as time)


DECLARE
#Now DateTime,
#Today DateTime,
#Time DateTime
SET #Now = GetDate()
SET #Today = DateAdd(dd, DateDiff(dd, 0, #Now), 0)
SET #Time = DateAdd(ss, DateDiff(ss, #Today, #Now), 0)
SELECT #Time


Just another way to get date and time from datetime.
datetime in SQL Server implemented as float value where whole part floor(value) is day from 1900-01-01 and fractional part (value - floor(value)) is part of twenty-four hours elapsed from start of day
select
d as [datetime],
cast(cast(T.d as float) - floor(cast(T.d as float)) as datetime) as [time],
cast(floor(cast(T.d as float)) as datetime) as [date]
from
(values
(getdate()),
('1753-01-01 23:59:59.700'),
('1899-12-31 00:00:00.300'),
('1900-01-01 00:00:00.300')
) as T(d);

Related

SQL Column Concatenation whilst keeping the datatype of first column [duplicate]

In an extract I am dealing with, I have 2 datetime columns. One column stores the dates and another the times as shown.
How can I query the table to combine these two fields into 1 column of type datetime?
Dates
2009-03-12 00:00:00.000
2009-03-26 00:00:00.000
2009-03-26 00:00:00.000
Times
1899-12-30 12:30:00.000
1899-12-30 10:00:00.000
1899-12-30 10:00:00.000

You can simply add the two.
if the Time part of your Date column is always zero
and the Date part of your Time column is also always zero (base date: January 1, 1900)
Adding them returns the correct result.
SELECT Combined = MyDate + MyTime FROM MyTable
Rationale (kudos to ErikE/dnolan)
It works like this due to the way the date is stored as two 4-byte
Integers with the left 4-bytes being the date and the right
4-bytes being the time. Its like doing $0001 0000 + $0000 0001 =
$0001 0001
Edit regarding new SQL Server 2008 types
Date and Time are types introduced in SQL Server 2008. If you insist on adding, you can use Combined = CAST(MyDate AS DATETIME) + CAST(MyTime AS DATETIME)
Edit2 regarding loss of precision in SQL Server 2008 and up (kudos to Martin Smith)
Have a look at How to combine date and time to datetime2 in SQL Server? to prevent loss of precision using SQL Server 2008 and up.

If the time element of your date column and the date element of your time column are both zero then Lieven's answer is what you need. If you can't guarantee that will always be the case then it becomes slightly more complicated:
SELECT DATEADD(day, 0, DATEDIFF(day, 0, your_date_column)) +
DATEADD(day, 0 - DATEDIFF(day, 0, your_time_column), your_time_column)
FROM your_table

This is an alternative solution without any char conversions:
DATEADD(ms, DATEDIFF(ms, '00:00:00', [Time]), CONVERT(DATETIME, [Date]))
You will only get milliseconds accuracy this way, but that would normally be OK. I have tested this in SQL Server 2008.

This worked for me
CAST(Tbl.date as DATETIME) + CAST(Tbl.TimeFrom AS TIME)
(on SQL 2008 R2)

If you're not using SQL Server 2008 (i.e. you only have a DateTime data type), you can use the following (admittedly rough and ready) TSQL to achieve what you want:
DECLARE #DateOnly AS datetime
DECLARE #TimeOnly AS datetime
SET #DateOnly = '07 aug 2009 00:00:00'
SET #TimeOnly = '01 jan 1899 10:11:23'
-- Gives Date Only.
SELECT DATEADD(dd, 0, DATEDIFF(dd, 0, #DateOnly))
-- Gives Time Only.
SELECT DATEADD(Day, -DATEDIFF(Day, 0, #TimeOnly), #TimeOnly)
-- Concatenates Date and Time parts.
SELECT
CAST(
DATEADD(dd, 0, DATEDIFF(dd, 0, #DateOnly)) + ' ' +
DATEADD(Day, -DATEDIFF(Day, 0, #TimeOnly), #TimeOnly)
as datetime)
It's rough and ready, but it works!

If both of your fields are datetime then simply adding those will work.
eg:
Declare #d datetime, #t datetime
set #d = '2009-03-12 00:00:00.000';
set #t = '1899-12-30 12:30:00.000';
select #d + #t
If you used Date & Time datatype then just cast the time to datetime
eg:
Declare #d date, #t time
set #d = '2009-03-12';
set #t = '12:30:00.000';
select #d + cast(#t as datetime)

This was my solution which ignores the date value of the time column
CAST(Tbl.date as DATETIME) + CAST(CAST(Tbl.TimeFrom AS TIME) as DATETIME)
Hope this helps others

Convert the first date stored in a datetime field to a string, then convert the time stored in a datetime field to string, append the two and convert back to a datetime field all using known conversion formats.
Convert(datetime, Convert(char(10), MYDATETIMEFIELD, 103) + ' ' + Convert(char(8), MYTIMEFIELD, 108), 103)

Convert both field into DATETIME :
SELECT CAST(#DateField as DATETIME) + CAST(#TimeField AS DATETIME)
and if you're using Getdate() use this first:
DECLARE #FechaActual DATETIME = CONVERT(DATE, GETDATE());
SELECT CAST(#FechaActual as DATETIME) + CAST(#HoraInicioTurno AS DATETIME)

I had many errors as stated above so I did it like this
try_parse(concat(convert(date,Arrival_date),' ',arrival_time) as datetime) AS ArrivalDateTime
It worked for me.

Finding this works for two dates where you want time from one and date from the other:
declare #Time as datetime = '2021-11-19 12:34'
declare #Date as datetime = '2021-10-10'
SELECT #time + datediff(day, #Time, #Date)

DECLARE #Dates table ([Date] datetime);
DECLARE #Times table ([Time] datetime);
INSERT INTO #Dates VALUES('2009-03-12 00:00:00.000');
INSERT INTO #Dates VALUES('2009-03-26 00:00:00.000');
INSERT INTO #Dates VALUES('2009-03-30 00:00:00.000');
INSERT INTO #Times VALUES('1899-12-30 12:30:00.000');
INSERT INTO #Times VALUES('1899-12-30 10:00:00.000');
INSERT INTO #Times VALUES('1899-12-30 10:00:00.000');
WITH Dates (ID, [Date])
AS (
SELECT ROW_NUMBER() OVER (ORDER BY [Date]), [Date] FROM #Dates
), Times (ID, [Time])
AS (
SELECT ROW_NUMBER() OVER (ORDER BY [Time]), [Time] FROM #Times
)
SELECT Dates.[Date] + Times.[Time] FROM Dates
JOIN Times ON Times.ID = Dates.ID
Prints:
2009-03-12 10:00:00.000
2009-03-26 10:00:00.000
2009-03-30 12:30:00.000

To combine date from a datetime column and time from another datetime column this is the best fastest solution for you:
select cast(cast(DateColumn as date) as datetime) + cast(TimeColumn as datetime) from YourTable

SELECT CAST(CAST(#DateField As Date) As DateTime) + CAST(CAST(#TimeField As Time) As DateTime)

Another way is to use CONCATand CAST, be aware, that you need to use DATETIME2(x) to make it work. You can set x to anything between 0-7 7 meaning no precision loss.
DECLARE #date date = '2018-03-12'
DECLARE #time time = '07:00:00.0000000'
SELECT CAST(CONCAT(#date, ' ', #time) AS DATETIME2(7))
Returns 2018-03-12 07:00:00.0000000
Tested on SQL Server 14

simply concatenate both , but cast them first as below
select cast(concat(Cast(DateField as varchar), ' ', Cast(TimeField as varchar)) as datetime) as DateWithTime from TableName;

select s.SalesID from SalesTbl s
where cast(cast(s.SaleDate as date) as datetime) + cast(cast(s.SaleCreatedDate as time) as datetime) between #FromDate and #ToDate

The existing answers do not address the datetime2 datatype so I will add mine:
Assuming that you want to add a time value to a datetime2 value where:
The datetime2 value could contain non-zero time component and/or fractional seconds
The time value could contain the value 23:59:59.9999999 which is 86,399.9999999 seconds, 86,399,999,999.9 microseconds or 86,399,999,999,900 nanoseconds¹
Due to the limitations of dateadd function¹ you must add them in two steps:
Convert the time value to seconds and use dateadd(second, ...)
Extract the nanoseconds from the time value and use dateadd(nanosecond, ...) to add them to the date calculated above
declare #dv datetime2 = '2000-01-01 12:34:56.7890123';
declare #tv time = '23:59:59.9999999';
select dateadd(
nanosecond,
datepart(nanosecond, #tv),
dateadd(
second,
datepart(hour, #tv) * 60 * 60 + datepart(minute, #tv) * 60 + datepart(second, #tv),
#dv
)
);
-- 2000-01-02 12:34:56.7890122
¹ Nanosecond values might not fit in int datatype which dateadd function expects.

SELECT CAST(your_date_column AS date) + CAST(your_time_column AS datetime) FROM your_table
Works like a charm

I ran into similar situation where I had to merge Date and Time fields to DateTime field. None of the above mentioned solution work, specially adding two fields as the data type for addition of these 2 fields is not same.
I created below solution, where I added hour and then minute part to the date. This worked beautifully for me. Please check it out and do let me know if you get into any issues.
;with tbl
as
(
select StatusTime = '12/30/1899 5:17:00 PM', StatusDate = '7/24/2019 12:00:00 AM'
)
select DATEADD(MI, DATEPART(MINUTE,CAST(tbl.StatusTime AS TIME)),DATEADD(HH, DATEPART(HOUR,CAST(tbl.StatusTime AS TIME)), CAST(tbl.StatusDate as DATETIME)))
from tbl
Result: 2019-07-24 17:17:00.000

Concatenate date and string to create datetime in SQL

I need to concatenate a datetime and a time field in SQL to a single date time.
e.g I have a datetime of 2017-09-05 00:00:00.000 and a string time of 11:00. What I want is a single field in a view of 2017-09-05 11:00:00.000
I have tried casting the datetime to a date and then concatenate the new date and string date field together but this doesn't work.
To cast the datetime I am using: CAST(dtDate AS DATE) AS dtNewDate which works fine. When I then use: CAST(dtNewDate + szTime AS datetime) AS dtNewDateTime the creation of the view works fine but selecting the top 1000 returns a "conversion failed when converting date and/or time from character string."
Is there an easier way to do this or can anyone offer some advise (other than storing the date and time in a single datetime field in the first place as it is populated by a third party application which I do not have access to change)

You can add two datetime values together, so try:
CAST(dtDate AS DATETIME) + CAST(CAST(szTime AS TIME) as DATETIME)

Assuming 11:00 stands for 11:00:00, you can do something like this:
SELECT dtDate + CONVERT(DateTime, szTime, 108)
FROM...
See a live demo on rextester

You can try following.
DECLARE #YourDate AS DATETIME
SET #YourDate = CONVERT(VARCHAR(10), '2017-09-05 00:00:00.000', 111) + ' 11:00'
PRINT #YourDate

another way is to get the hour from your stringfield, convert it to int, and add that as hours to the datetime
declare #date datetime = '20170905'
declare #stringtime varchar(5) = '11:00'
select left(#stringtime, 2),
dateadd(hour, convert(int, left(#stringtime, 2)), #date)
If you also need the minutes you can do it like this :
declare #date datetime = '20170905'
declare #stringtime varchar(5) = '11:05'
select left(#stringtime, 2),
right(#stringtime, 2),
dateadd(minute, convert(int, right(#stringtime, 2)), dateadd(hour, convert(int, left(#stringtime, 2)), #date))
This will only work if the stringfield is always in format hh:mm

If you care about precision with DATETIME2,
DECLARE #D DATETIME = '2017-01-01';
DECLARE #T varchar(7) = '11:00';
SELECT DATEADD(day, DATEDIFF(day, '19000101', #D), CAST(CAST(#T AS TIME) AS DATETIME2(7)));
Running example here

Query of set time range relative to current date

I come in to work 6.30am, and need to audit what happened from 5pm when I left to 6.30am this morning. I have used code to search 13.5 hours back from any given time:
SELECT * FROM TRANSACTION_HISTORY
WHERE TRANSACTION_HISTORY.ACTIVITY_DATE_TIME > (SELECT DATEADD(hour,-13.5,(SELECT MAX (TRANSACTION_HISTORY.ACTIVITY_DATE_TIME) FROM TRANSACTION_HISTORY)))
Problem is if I run query later, I lose time from the start, eg. If I run query at 7am, I only get results from 5.30pm onwards. Rather than change criteria every day, I wanted to able to search from 6.30am of the current day, back to 5.30pm of the previous day. Can this be done?

Normally, I don't advise using between for datetime, because the boundary conditions can cause confusion. I don't think that is the case.
Here is one method:
SELECT *
FROM TRANSACTION_HISTORY th
WHERE th.ACTIVITY_DATE_TIME between cast(cast(getdate() -1 as date) as datetime) + 17.5/24.0
cast(cast(getdate() as date) as datetime) + 6.5/24.0;
The expression cast(cast(getdate() as date) as datetime) is truncating the datetime value to midnight. As a datetime, SQL Server lets you add a number which is understood as a fraction of a day. Hence, 17.5/24 represents "5:30". This addition doesn't work for the date data type.

You can do this.
DECLARE #dt datetime
DECLARE #dt1 datetime
DECLARE #dt2 datetime
SET #dt = CONVERT(datetime, CONVERT(VARCHAR(10), getdate(), 101 ), 101)
SET #dt1 = dateadd(mi, 30, dateadd(hh, 6, #dt))
SET #dt2 = dateadd(mi, -27*30, #dt1)
SELECT #dt1 as StartDate, #dt2 as EndDate
For additional details what this script does you may check these pages.
http://technet.microsoft.com/en-us/library/ms174450%28v=sql.105%29.aspx
http://technet.microsoft.com/en-us/library/ms186819%28v=sql.105%29.aspx

Convert datetime and varchar to single date

I have a following database columns and the values
MyDate datetime and My_Time varchar(5)
the values stored are
2006-09-05 00:00:00.000 and 16:47
Now I want to add this two columns and get a single datetime value 2006-09-05 16:47:00.000
How can I do this in SQL ?
UPDATE:
Some rows have NULL values for DocDate and DocTime.
So i am getting error like Conversion failed when converting date and/or time from character string

Simply...
DECLARE #date DATETIME
DECLARE #time VARCHAR(5)
SET #date = '2006-09-05 00:00:00.000'
SET #time = '16:47'
SELECT CAST(#date + #time AS DATETIME) -- 2006-09-05 16:47:00.000

Try this:
select dateadd(ss, datediff(ss, 0, #My_Time), #MyDate)
Key point is to understand that it's the same as...
select dateadd(ss, datediff(ss, 0, cast(#My_Time as time)), #MyDate)
...but the conversion is done explicitly.
EDIT
For default time and/or date, use ISNULL or COALESCE as appropriate.
Example:
SELECT
CAST(
isnull(#date, '2000-1-1') +
isnull(#time, '0:0')
AS DATETIME)

Try
CAST(MyDate AS DATETIME) + CAST(MyTime AS DATETIME) as CombinedDate

How to combine date from one field with time from another field - MS SQL Server

In an extract I am dealing with, I have 2 datetime columns. One column stores the dates and another the times as shown.
How can I query the table to combine these two fields into 1 column of type datetime?
Dates
2009-03-12 00:00:00.000
2009-03-26 00:00:00.000
2009-03-26 00:00:00.000
Times
1899-12-30 12:30:00.000
1899-12-30 10:00:00.000
1899-12-30 10:00:00.000

You can simply add the two.
if the Time part of your Date column is always zero
and the Date part of your Time column is also always zero (base date: January 1, 1900)
Adding them returns the correct result.
SELECT Combined = MyDate + MyTime FROM MyTable
Rationale (kudos to ErikE/dnolan)
It works like this due to the way the date is stored as two 4-byte
Integers with the left 4-bytes being the date and the right
4-bytes being the time. Its like doing $0001 0000 + $0000 0001 =
$0001 0001
Edit regarding new SQL Server 2008 types
Date and Time are types introduced in SQL Server 2008. If you insist on adding, you can use Combined = CAST(MyDate AS DATETIME) + CAST(MyTime AS DATETIME)
Edit2 regarding loss of precision in SQL Server 2008 and up (kudos to Martin Smith)
Have a look at How to combine date and time to datetime2 in SQL Server? to prevent loss of precision using SQL Server 2008 and up.

If the time element of your date column and the date element of your time column are both zero then Lieven's answer is what you need. If you can't guarantee that will always be the case then it becomes slightly more complicated:
SELECT DATEADD(day, 0, DATEDIFF(day, 0, your_date_column)) +
DATEADD(day, 0 - DATEDIFF(day, 0, your_time_column), your_time_column)
FROM your_table

This is an alternative solution without any char conversions:
DATEADD(ms, DATEDIFF(ms, '00:00:00', [Time]), CONVERT(DATETIME, [Date]))
You will only get milliseconds accuracy this way, but that would normally be OK. I have tested this in SQL Server 2008.

This worked for me
CAST(Tbl.date as DATETIME) + CAST(Tbl.TimeFrom AS TIME)
(on SQL 2008 R2)

If you're not using SQL Server 2008 (i.e. you only have a DateTime data type), you can use the following (admittedly rough and ready) TSQL to achieve what you want:
DECLARE #DateOnly AS datetime
DECLARE #TimeOnly AS datetime
SET #DateOnly = '07 aug 2009 00:00:00'
SET #TimeOnly = '01 jan 1899 10:11:23'
-- Gives Date Only.
SELECT DATEADD(dd, 0, DATEDIFF(dd, 0, #DateOnly))
-- Gives Time Only.
SELECT DATEADD(Day, -DATEDIFF(Day, 0, #TimeOnly), #TimeOnly)
-- Concatenates Date and Time parts.
SELECT
CAST(
DATEADD(dd, 0, DATEDIFF(dd, 0, #DateOnly)) + ' ' +
DATEADD(Day, -DATEDIFF(Day, 0, #TimeOnly), #TimeOnly)
as datetime)
It's rough and ready, but it works!

If both of your fields are datetime then simply adding those will work.
eg:
Declare #d datetime, #t datetime
set #d = '2009-03-12 00:00:00.000';
set #t = '1899-12-30 12:30:00.000';
select #d + #t
If you used Date & Time datatype then just cast the time to datetime
eg:
Declare #d date, #t time
set #d = '2009-03-12';
set #t = '12:30:00.000';
select #d + cast(#t as datetime)

This was my solution which ignores the date value of the time column
CAST(Tbl.date as DATETIME) + CAST(CAST(Tbl.TimeFrom AS TIME) as DATETIME)
Hope this helps others

Convert the first date stored in a datetime field to a string, then convert the time stored in a datetime field to string, append the two and convert back to a datetime field all using known conversion formats.
Convert(datetime, Convert(char(10), MYDATETIMEFIELD, 103) + ' ' + Convert(char(8), MYTIMEFIELD, 108), 103)

Convert both field into DATETIME :
SELECT CAST(#DateField as DATETIME) + CAST(#TimeField AS DATETIME)
and if you're using Getdate() use this first:
DECLARE #FechaActual DATETIME = CONVERT(DATE, GETDATE());
SELECT CAST(#FechaActual as DATETIME) + CAST(#HoraInicioTurno AS DATETIME)

I had many errors as stated above so I did it like this
try_parse(concat(convert(date,Arrival_date),' ',arrival_time) as datetime) AS ArrivalDateTime
It worked for me.

Finding this works for two dates where you want time from one and date from the other:
declare #Time as datetime = '2021-11-19 12:34'
declare #Date as datetime = '2021-10-10'
SELECT #time + datediff(day, #Time, #Date)

DECLARE #Dates table ([Date] datetime);
DECLARE #Times table ([Time] datetime);
INSERT INTO #Dates VALUES('2009-03-12 00:00:00.000');
INSERT INTO #Dates VALUES('2009-03-26 00:00:00.000');
INSERT INTO #Dates VALUES('2009-03-30 00:00:00.000');
INSERT INTO #Times VALUES('1899-12-30 12:30:00.000');
INSERT INTO #Times VALUES('1899-12-30 10:00:00.000');
INSERT INTO #Times VALUES('1899-12-30 10:00:00.000');
WITH Dates (ID, [Date])
AS (
SELECT ROW_NUMBER() OVER (ORDER BY [Date]), [Date] FROM #Dates
), Times (ID, [Time])
AS (
SELECT ROW_NUMBER() OVER (ORDER BY [Time]), [Time] FROM #Times
)
SELECT Dates.[Date] + Times.[Time] FROM Dates
JOIN Times ON Times.ID = Dates.ID
Prints:
2009-03-12 10:00:00.000
2009-03-26 10:00:00.000
2009-03-30 12:30:00.000

To combine date from a datetime column and time from another datetime column this is the best fastest solution for you:
select cast(cast(DateColumn as date) as datetime) + cast(TimeColumn as datetime) from YourTable

SELECT CAST(CAST(#DateField As Date) As DateTime) + CAST(CAST(#TimeField As Time) As DateTime)

Another way is to use CONCATand CAST, be aware, that you need to use DATETIME2(x) to make it work. You can set x to anything between 0-7 7 meaning no precision loss.
DECLARE #date date = '2018-03-12'
DECLARE #time time = '07:00:00.0000000'
SELECT CAST(CONCAT(#date, ' ', #time) AS DATETIME2(7))
Returns 2018-03-12 07:00:00.0000000
Tested on SQL Server 14

simply concatenate both , but cast them first as below
select cast(concat(Cast(DateField as varchar), ' ', Cast(TimeField as varchar)) as datetime) as DateWithTime from TableName;

select s.SalesID from SalesTbl s
where cast(cast(s.SaleDate as date) as datetime) + cast(cast(s.SaleCreatedDate as time) as datetime) between #FromDate and #ToDate

The existing answers do not address the datetime2 datatype so I will add mine:
Assuming that you want to add a time value to a datetime2 value where:
The datetime2 value could contain non-zero time component and/or fractional seconds
The time value could contain the value 23:59:59.9999999 which is 86,399.9999999 seconds, 86,399,999,999.9 microseconds or 86,399,999,999,900 nanoseconds¹
Due to the limitations of dateadd function¹ you must add them in two steps:
Convert the time value to seconds and use dateadd(second, ...)
Extract the nanoseconds from the time value and use dateadd(nanosecond, ...) to add them to the date calculated above
declare #dv datetime2 = '2000-01-01 12:34:56.7890123';
declare #tv time = '23:59:59.9999999';
select dateadd(
nanosecond,
datepart(nanosecond, #tv),
dateadd(
second,
datepart(hour, #tv) * 60 * 60 + datepart(minute, #tv) * 60 + datepart(second, #tv),
#dv
)
);
-- 2000-01-02 12:34:56.7890122
¹ Nanosecond values might not fit in int datatype which dateadd function expects.

SELECT CAST(your_date_column AS date) + CAST(your_time_column AS datetime) FROM your_table
Works like a charm

I ran into similar situation where I had to merge Date and Time fields to DateTime field. None of the above mentioned solution work, specially adding two fields as the data type for addition of these 2 fields is not same.
I created below solution, where I added hour and then minute part to the date. This worked beautifully for me. Please check it out and do let me know if you get into any issues.
;with tbl
as
(
select StatusTime = '12/30/1899 5:17:00 PM', StatusDate = '7/24/2019 12:00:00 AM'
)
select DATEADD(MI, DATEPART(MINUTE,CAST(tbl.StatusTime AS TIME)),DATEADD(HH, DATEPART(HOUR,CAST(tbl.StatusTime AS TIME)), CAST(tbl.StatusDate as DATETIME)))
from tbl
Result: 2019-07-24 17:17:00.000