What is the difference between char, nchar, varchar, and nvarchar in SQL Server?

Just to clear up... or sum up...

• nchar and nvarchar can store Unicode characters.
• char and varchar cannot store Unicode characters.
• char and nchar are fixed-length which will reserve storage space for number of characters you specify even if you don't use up all that space.
• varchar and nvarchar are variable-length which will only use up spaces for the characters you store. It will not reserve storage like char or nchar.

nchar and nvarchar will take up twice as much storage space, so it may be wise to use them only if you need Unicode support.

nchar and char pretty much operate in exactly the same way as each other, as do nvarchar and varchar. The only difference between them is that nchar/nvarchar store Unicode characters (essential if you require the use of extended character sets) whilst varchar does not.

Because Unicode characters require more storage, nchar/nvarchar fields take up twice as much space (so for example in earlier versions of SQL Server the maximum size of an nvarchar field is 4000).

This question is a duplicate of this one.

nchar(10) is a fixed-length Unicode string of length 10. nvarchar(10) is a variable-length Unicode string with a maximum length of 10. Typically, you would use the former if all data values are 10 characters and the latter if the lengths vary.

nchar requires more space than nvarchar.

eg,

A nchar(100) will always store 100 characters even if you only enter 5, the remaining 95 chars will be padded with spaces. Storing 5 characters in a nvarchar(100) will save 5 characters.

• nchar is fixed-length and can hold unicode characters. it uses two bytes storage per character.

• varchar is of variable length and cannot hold unicode characters. it uses one byte storage per character.

NVARCHAR can store Unicode characters and takes 2 bytes per character.