nvarchar

I am really surprisde to see that in my MS SQL table, I am defining a field varchar and doing group by with another table's field. When I do the same thing with the column as nvarchar it is 3 second faster than varchar when, theoretically, varchar should be faster because of 1 byte char. Can anyone explain me why nvarchar is faster in this instance? Thanks in advance. Operating systems use Unicode internally. I think that makes nvarchar faster since it does not need any converting. 来源： https://stackoverflow.com/questions/6250728/nvarchar-perform-better-than-varchar

When designing a database, what decisions do you consider when deciding how big your nvarchar should be. If i was to make an address table my gut reaction would be for address line 1 to be nvarchar(255) like an old access database. I have found using this has got me in bother with the old 'The string would be truncated'. I know that this can be prevented by limiting the input box but if a user really has a address line one that is over 255 this should be allowed. How big should I make my nvarchar(????) My recommendation: make them just as big as you REALLY need them. E.g. for a zip code column

I have a SQL Server 2008 R2 table with nvarchar(4000) field. Data that stores this table look like '696D616765206D61726B65643A5472' or '303131' ("011") . I see that each char is encoding to hex. How can I read those data from table? I don't want write decoding function, I mean that simpler way exists. P.S. Sorry for my English. SQL Server 2008 actually has a built-in hex-encoding and decoding feature! Sample (note the third parameter with value "1" when converting your string to VarBinary): DECLARE @ProblemString VarChar(4000) = '54657374' SELECT Convert(VarChar, Convert(VarBinary, '0x' +

I am trying to insert ≤ and ≥ into a symbol table where the column is of type nvarchar . Is this possible or are these symbols not allowed in SQL Server? Gonzalo.- To make it work, prefix the string with N create table symboltable ( val nvarchar(10) ) insert into symboltable values(N'≥') select * from symboltable Further Reading : You must precede all Unicode strings with a prefix N when you deal with Unicode string constants in SQL Server Why do some SQL strings have an 'N' prefix? To add to gonzalo's answer, both the string literal and the field need to support unicode characters . String

I've read all about varchar versus nvarchar. But I didn't see an answer to what I think is a simple question. How do you determine the length of your nvarchar column? For varchar it's very simple: my Description, for example, can have 100 characters, so I define varchar(100). Now I'm told we need to internationalize and support any language. Does this mean I need to change my Description column to nvarchar(200), i.e. simply double the length? (And I'm ignoring all the other issues that are involved with internationalization for the moment.) Is it that simple? Generally it is the same as for

I am trying to do something like this... public static List<string> GetAttachmentKeyList() { DataClassesDataContext dc = new DataClassesDataContext(); List<string> list = from a in dc.Attachments select a.Att_Key.ToString().ToList(); return list; } Visual Studio is saying... Cannot implicitly convert type 'System.Linq.IQueryable>' to 'System.Collections.Generic.List'. An explicit conversion exists (are you missing a cast?) What is the proper syntax??? Give this a try public static List<string> GetAttachmentKeyList() { DataClassesDataContext dc = new DataClassesDataContext(); List<string> list