Changing an nvarchar column to datetime I am new to SQL Server and I have a problem.

I created a database to store dates in an nvarchar field but now I need to convert that field to datetime. I searched the internet and couldn't find a proper solution.

One thing I found was to create a new datetime column, copy string value to that, then rename the new column to original one.

My string value format is 21/11/2014. I need to keep the same format. If anyone could give me a SQL Server query that can do that, I'd highly appreciate. I'm using SQL Server Management Studio 2014.
As you mention you string value format is in 21/11/2105 then you can try following one 

Alter table table name alter column column name datetime NULL


( null is optional if you want to allow null value to your field).

Note that if the column contain  string value like "abc" (other than date format value) then it will show error as conversion fail.