Question

In SQL Server, the query

SELECT custid, country, region, city
FROM Sales.Customers
WHERE region = N'WA'

what is the meaning of ‘N’ in the where clause? I remove it, get same result.

Answer 1

Unicode string constants that appear in code executed on the server, such as in stored procedures and triggers, must be preceded by the capital letter N. This is true even if the column being referenced is already defined as Unicode. Without the N prefix, the string is converted to the default code page of the database. This may not recognize certain characters.

For example, the stored procedure created in the previous example can be executed on the server in the following way:

EXECUTE Product_Info @name = N'Chain'

The requirement to use the N prefix applies to both string constants that originate on the server and those sent from the client.