how to convert nvarchar(50) to datetime in sqlserver 2008 - sql

Question

hi i wrote this query in SqlServer 2008
but some thing goes wrong
select * from News_Table
where (DATEDIFF( DAY ,convert(datetime, NewsDate) , convert(datetime,#Todaydate )) <= #Count)
that #NewsDate and #Todaydate are two nvarchar parameters that are saved like this 2014/11/16
running this query give me an error:
Conversion failed when converting date and/or time from character string

Answer 1

Try adding the correct style parameter to your convert function (see MSDN: link )
ie CONVERT(DATETIME, NewsDate, 111) (111 is the style for YYYY/MM/DD)
Then you get:
SELECT *
FROM News_Table
WHERE (DATEDIFF( DAY ,
CONVERT(DATETIME, NewsDate, 111) ,
CONVERT(DATETIME,#Todaydate, 111)
) <= #Count)

Answer 2

use Convert(datetime, #yourvalue, 111)
select * from News_Table
where (DATEDIFF( DAY ,convert(datetime, #NewsDate, 111) , convert(datetime,#Todaydate, 111 )) <= #Count)
http://www.sqlusa.com/bestpractices/datetimeconversion/

Answer 3

To know more click here
SELECT convert(datetime, '2014/11/16', 111) as datetime
OP
So your query would be like this
Select * from News_Table
where (DATEDIFF( DAY ,convert(datetime, '2014/11/16', 111) , convert(datetime,#Todaydate,111 )) <= #Count)

Answer 4

Try like this
SELECT *
FROM News_Table
WHERE (DATEDIFF(DAY,CAST(NewsDate AS Datetime),CAST(#Todaydate AS Datetime)) <= #Count)

Answer 5

You will need to do something like this to convert that string into DATETIME datatype
DECLARE #Date NVARCHAR(20) = '2013/11/16'
SELECT CAST((LEFT(#Date, 4) + SUBSTRING(#Date, 6 ,2) + RIGHT(#Date, 2)) AS DATETIME)
for your query
select * from News_Table
where (DATEDIFF( DAY , CAST((LEFT(NewsDate, 4) + SUBSTRING(NewsDate, 6 ,2) + RIGHT(NewsDate, 2)) AS DATETIME)
, CAST((LEFT(#Todaydate, 4) + SUBSTRING(#Todaydate, 6 ,2) + RIGHT(#Todaydate, 2)) AS DATETIME)
) <= #Count)
Note
If variable #Todaydate is actually storing today's date then why not use simply GETDATE() function.