Difference between the VARCHAR and NVARCHAR Data Type in Sql Server

In this article I am explain, difference between the VARCHAR andNVARCHAR Data Type in Sql Serve.

Below table lists out the major difference between the VARCHAR and

NVARCHAR Data Type in Sql Server:

	Varchar[(n)]	NVarchar[(n)]
Basic Definition	Non-Unicode Variable Length character data type. Example: DECLARE @FirstName AS VARCHAR(50) ='Jitendra' SELECT @FirstName	UNicode Variable Length character data type. It can store both non-Unicode and Unicode (i.e. Japanese, Korean etc) characters. Example: DECLARE @FirstName AS NVARCHAR(50)= 'Jitendra' SELECT @FirstName
No. of Bytes required for each character	It takes 1 byte per character Example: DECLARE @FirstName AS VARCHAR(50) = 'Jitendra' SELECT @FirstName AS FirstName, DATALENGTH(@FirstName) AS  Length Result: FirstName LengthJitendra 8	It takes 2 bytes per Unicode/Non-Unicode character. Example: DECLARE @FirstName AS NVARCHAR(50)= 'Jitendra' SELECT @FirstName AS FirstName, DATALENGTH(@FirstName) AS Length Result: FirstName Length Jitendra 16
Optional Parameter nrange	Optional Parameter n value can be from 1 to 8000.Can store maximum 8000 Non-Unicode characters.	Optional Parameter n value can be from 1 to 4000.Can store maximum 4000 Unicode/Non-Unicode characters
If Optional Parameter nis not specified in the variable declaration or column definition	If Optional parameter value n is not specified in the variable declaration or column definition then it is considered as 1. Example: DECLARE @firstName VARCHAR ='Jitendra' SELECT @firstName FirstName,DATALENGTH(@firstName) Length Result: FirstName Length J 1	If Optional parameter value n is not specified in the variable declaration or column definition then it is considered as 1. Example: DECLARE @firstName NVARCHAR ='Jitendra' SELECT @firstName FirstName,DATALENGTH(@firstName) Length Result: FirstName Length J 2
If Optional Parameter nis not specified in while using CAST/ CONVERT functions	When this optional parameter n is not specified while using the CAST/CONVERT functions, then it is considered as 22.Example: DECLARE @firstName VARCHAR(22)= 'Jitendra Gangwar INDIA ASIA' SELECT CAST(@firstName AS VARCHAR) FirstName, DATALENGTH(CAST(@firstName AS VARCHAR)) Length Result: FirstName Length Jitendra Gangwar INDIA 22	When this optional parameter n is not specified while using the CAST CONVERT functions, then it is considered as 22.Example: DECLARE @firstName NVARCHAR(22)= 'Jitendra Gangwar INDIA ASIA' SELECT CAST(@firstName AS'NVARCHAR) FirstName, DATALENGTH(CAST(@firstName AS'NVARCHAR)) Length Result: FirstName Length Jitendra Gangwar INDIA 44
Which one to use?	If we know that data to be stored in the column or variable doesn’t have any Unicode characters.	If we know that the data to be stored in the column or variable can have Unicode characters.
Storage Size	Takes no. of bytes equal to the no. of Characters entered plus two bytes extra for defining offset.	Takes no. of bytes equal to twice the no. of Characters entered plus two bytes extra for defining offset.

As both of these are variable length datatypes, so irrespective of the

length (i.e. optional parameter n value) defined in the variable

declaration/column definition it will always take the no. of bytes required

for the actual characters stored. The value of n defines maximum no. of

characters that can be stored.