What does N do? 1

[RiddleMeThis]

What does N do? I'm looking at some code which I understand for the most part, but if I were writing it I wouldnt use N in it, I don't know what N does so was just wondering if someone could explain it to me please.

EXAMPLE:
SELECT * FROM sys.objects WHERE type IN (N'P', N'PC')

 

[bborissov]

It converts the string that is immediately after the n to NVARCHAR.

Borislav Borissov
VFP9 SP2, SQL Server 2000/2005.

 

[RiddleMeThis]

ok thanks, i would have thought that a string would automatically be converted to the correct string type though. Does any hardcoded nvarchar need to have an N before the actual string then?

 

[RiddleMeThis]

I tried the example i gave in the first post with and without the N and i get the same results for both. So why do we need the N?

EXAMPLES:

SELECT * FROM sys.objects WHERE type IN (N'P', N'PC')

SELECT * FROM sys.objects WHERE type IN ('P', 'PC')

 

[bborissov]

When you put N' SQL Server knows that the text after that is NVARCHAR. When you didn't put N SQL Server checks the field type and after that it decides if it must convert the text or not.
In other words with N' your query will be a little bit faster


Borislav Borissov
VFP9 SP2, SQL Server 2000/2005.

 

[RiddleMeThis]

Ah I see, thanks for that you've cleared things up for me

 

[tcsbiz]

I always thought the N meant the string was a unicode string instead of a string based on the Engilsh character set.

 

[bborissov]

NVARCHAR is just that - an UNICODE string

Borislav Borissov
VFP9 SP2, SQL Server 2000/2005.