问题
I am working on a query in Sql Server 2005 where I need to convert a value in DateTime variable into a varchar variable in yyyy-mm-dd format (without time part). How do I do that?
回答1:
With Microsoft Sql Server:
--
-- Create test case
--
DECLARE @myDateTime DATETIME
SET @myDateTime = '2008-05-03'
--
-- Convert string
--
SELECT LEFT(CONVERT(VARCHAR, @myDateTime, 120), 10)
回答2:
Here's some test sql for all the styles.
DECLARE @now datetime
SET @now = GETDATE()
select convert(nvarchar(MAX), @now, 0) as output, 0 as style
union select convert(nvarchar(MAX), @now, 1), 1
union select convert(nvarchar(MAX), @now, 2), 2
union select convert(nvarchar(MAX), @now, 3), 3
union select convert(nvarchar(MAX), @now, 4), 4
union select convert(nvarchar(MAX), @now, 5), 5
union select convert(nvarchar(MAX), @now, 6), 6
union select convert(nvarchar(MAX), @now, 7), 7
union select convert(nvarchar(MAX), @now, 8), 8
union select convert(nvarchar(MAX), @now, 9), 9
union select convert(nvarchar(MAX), @now, 10), 10
union select convert(nvarchar(MAX), @now, 11), 11
union select convert(nvarchar(MAX), @now, 12), 12
union select convert(nvarchar(MAX), @now, 13), 13
union select convert(nvarchar(MAX), @now, 14), 14
--15 to 19 not valid
union select convert(nvarchar(MAX), @now, 20), 20
union select convert(nvarchar(MAX), @now, 21), 21
union select convert(nvarchar(MAX), @now, 22), 22
union select convert(nvarchar(MAX), @now, 23), 23
union select convert(nvarchar(MAX), @now, 24), 24
union select convert(nvarchar(MAX), @now, 25), 25
--26 to 99 not valid
union select convert(nvarchar(MAX), @now, 100), 100
union select convert(nvarchar(MAX), @now, 101), 101
union select convert(nvarchar(MAX), @now, 102), 102
union select convert(nvarchar(MAX), @now, 103), 103
union select convert(nvarchar(MAX), @now, 104), 104
union select convert(nvarchar(MAX), @now, 105), 105
union select convert(nvarchar(MAX), @now, 106), 106
union select convert(nvarchar(MAX), @now, 107), 107
union select convert(nvarchar(MAX), @now, 108), 108
union select convert(nvarchar(MAX), @now, 109), 109
union select convert(nvarchar(MAX), @now, 110), 110
union select convert(nvarchar(MAX), @now, 111), 111
union select convert(nvarchar(MAX), @now, 112), 112
union select convert(nvarchar(MAX), @now, 113), 113
union select convert(nvarchar(MAX), @now, 114), 114
union select convert(nvarchar(MAX), @now, 120), 120
union select convert(nvarchar(MAX), @now, 121), 121
--122 to 125 not valid
union select convert(nvarchar(MAX), @now, 126), 126
union select convert(nvarchar(MAX), @now, 127), 127
--128, 129 not valid
union select convert(nvarchar(MAX), @now, 130), 130
union select convert(nvarchar(MAX), @now, 131), 131
--132 not valid
order BY style
Here's the result
output style
Apr 28 2014 9:31AM 0
04/28/14 1
14.04.28 2
28/04/14 3
28.04.14 4
28-04-14 5
28 Apr 14 6
Apr 28, 14 7
09:31:28 8
Apr 28 2014 9:31:28:580AM 9
04-28-14 10
14/04/28 11
140428 12
28 Apr 2014 09:31:28:580 13
09:31:28:580 14
2014-04-28 09:31:28 20
2014-04-28 09:31:28.580 21
04/28/14 9:31:28 AM 22
2014-04-28 23
09:31:28 24
2014-04-28 09:31:28.580 25
Apr 28 2014 9:31AM 100
04/28/2014 101
2014.04.28 102
28/04/2014 103
28.04.2014 104
28-04-2014 105
28 Apr 2014 106
Apr 28, 2014 107
09:31:28 108
Apr 28 2014 9:31:28:580AM 109
04-28-2014 110
2014/04/28 111
20140428 112
28 Apr 2014 09:31:28:580 113
09:31:28:580 114
2014-04-28 09:31:28 120
2014-04-28 09:31:28.580 121
2014-04-28T09:31:28.580 126
2014-04-28T09:31:28.580 127
28 جمادى الثانية 1435 9:31:28:580AM 130
28/06/1435 9:31:28:580AM 131
Make nvarchar(max) shorter to trim the time. For example:
select convert(nvarchar(11), GETDATE(), 0)
union select convert(nvarchar(max), GETDATE(), 0)
outputs:
May 18 2018
May 18 2018 9:57AM
回答3:
Try the following:
CONVERT(varchar(10), [MyDateTimecolumn], 20)
For a full date time and not just date do:
CONVERT(varchar(23), [MyDateTimecolumn], 121)
See this page for convert styles:
http://msdn.microsoft.com/en-us/library/ms187928.aspx
OR
SQL Server CONVERT() Function
回答4:
SQL Server 2012 has a new function , FORMAT: http://msdn.microsoft.com/en-us/library/ee634924.aspx
and you can use custom date time format strings: http://msdn.microsoft.com/en-us/library/ee634398.aspx
These pages imply it is also available on SQL2008R2, but I don't have one handy to test if that's the case.
Example usage (Australian datetime):
FORMAT(VALUE,'dd/MM/yyyy h:mm:ss tt')
回答5:
Either Cast or Convert:
Syntax for CAST:
CAST ( expression AS data_type [ (length ) ])
Syntax for CONVERT:
CONVERT ( data_type [ ( length ) ] , expression [ , style ] )
http://msdn.microsoft.com/en-us/library/ms187928.aspx
Actually since you asked for a specific format:
REPLACE(CONVERT(varchar(10), Date, 102), '.', '-')
回答6:
You can use DATEPART(DATEPART, VARIABLE). For example:
DECLARE @DAY INT
DECLARE @MONTH INT
DECLARE @YEAR INT
DECLARE @DATE DATETIME
@DATE = GETDATE()
SELECT @DAY = DATEPART(DAY,@DATE)
SELECT @MONTH = DATEPART(MONTH,@DATE)
SELECT @YEAR = DATEPART(YEAR,@DATE)
回答7:
-- This gives you the time as 0 in format 'yyyy-mm-dd 00:00:00.000'
SELECT CAST( CONVERT(VARCHAR, GETDATE(), 101) AS DATETIME) ;
回答8:
With Microsoft SQL Server:
Use Syntax for CONVERT:
CONVERT ( data_type [ ( length ) ] , expression [ , style ] )
Example:
SELECT CONVERT(varchar,d.dateValue,1-9)
For the style you can find more info here: MSDN - Cast and Convert (Transact-SQL).
回答9:
Try:
select replace(convert(varchar, getdate(), 111),'/','-');
More on ms sql tips
回答10:
Try the following:
CONVERT(VARCHAR(10),GetDate(),102)
Then you would need to replace the "." with "-".
Here is a site that helps http://www.mssqltips.com/tip.asp?tip=1145
回答11:
declare @dt datetime
set @dt = getdate()
select convert(char(10),@dt,120)
I have fixed data length of char(10) as you want a specific string format.
回答12:
The OP mentioned datetime format. For me, the time part gets in the way.
I think it's a bit cleaner to remove the time portion (by casting datetime to date) before formatting.
convert( varchar(10), convert( date, @yourDate ) , 111 )
回答13:
This is how I do it: CONVERT(NVARCHAR(10), DATE1, 103) )
回答14:
You can convert your date in many formats, the syntaxe is simple to use :
CONVERT('TheTypeYouWant', 'TheDateToConvert', 'TheCodeForFormating' * )
CONVERT(NVARCHAR(10), DATE_OF_DAY, 103) => 15/09/2016
- The code is an integer, here 3 is the third formating without century, if you want the century just change the code to 103.
In your case, i've just converted and restrict size by nvarchar(10) like this :
CONVERT(NVARCHAR(10), MY_DATE_TIME, 120) => 2016-09-15
See more at : http://www.w3schools.com/sql/func_convert.asp
Another solution (if your date is a Datetime) is a simple CAST :
CAST(MY_DATE_TIME as DATE) => 2016-09-15
回答15:
Try this SQL:
select REPLACE(CONVERT(VARCHAR(24),GETDATE(),103),'/','_') + '_'+
REPLACE(CONVERT(VARCHAR(24),GETDATE(),114),':','_')
回答16:
For SQL Server 2008+ You can use CONVERT and FORMAT together.
For example, for European style (e.g. Germany) timestamp:
CONVERT(VARCHAR, FORMAT(GETDATE(), 'dd.MM.yyyy HH:mm:ss', 'de-DE'))
回答17:
You did not say which database, but with mysql here is an easy way to get a date from a timestamp (and the varchar type conversion should happen automatically):
mysql> select date(now());
+-------------+
| date(now()) |
+-------------+
| 2008-09-16 |
+-------------+
1 row in set (0.00 sec)
回答18:
The shortest and the simplest way is :
DECLARE @now AS DATETIME = GETDATE()
SELECT CONVERT(VARCHAR, @now, 23)
回答19:
DECLARE @DateTime DATETIME
SET @DateTime = '2018-11-23 10:03:23'
SELECT CONVERT(VARCHAR(100),@DateTime,121 )
回答20:
CONVERT(VARCHAR, GETDATE(), 23)
回答21:
Write a function
CREATE FUNCTION dbo.TO_SAP_DATETIME(@input datetime)
RETURNS VARCHAR(14)
AS BEGIN
DECLARE @ret VARCHAR(14)
SET @ret = COALESCE(SUBSTRING(REPLACE(REPLACE(REPLACE(CONVERT(VARCHAR(26), @input, 25),'-',''),' ',''),':',''),1,14),'00000000000000');
RETURN @ret
END
回答22:
You don't say what language but I am assuming C#/.NET because it has a native DateTime data type. In that case just convert it using the ToString method and use a format specifier such as:
DateTime d = DateTime.Today;
string result = d.ToString("yyyy-MM-dd");
However, I would caution against using this in a database query or concatenated into a SQL statement. Databases require a specific formatting string to be used. You are better off zeroing out the time part and using the DateTime as a SQL parameter if that is what you are trying to accomplish.
来源：https://stackoverflow.com/questions/74385/how-to-convert-datetime-to-varchar