What is the meaning of the prefix N in T-SQL statements and when should I use it?

Question

I have seen prefix N in some insert T-SQL queries. Many people have used N before inserting the value in a table.

I searched, but I was not able to unde

Answer 1

It's declaring the string as nvarchar data type, rather than varchar

You may have seen Transact-SQL code that passes strings around using an N prefix. This denotes that the subsequent string is in Unicode (the N actually stands for National language character set). Which means that you are passing an NCHAR, NVARCHAR or NTEXT value, as opposed to CHAR, VARCHAR or TEXT.

To quote from Microsoft:

Prefix Unicode character string constants with the letter N. Without the N prefix, the string is converted to the default code page of the database. This default code page may not recognize certain characters.

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If you want to know the difference between these two data types, see this SO post:

What is the difference between varchar and nvarchar?