Autoincrement uniqueidentifier

Question

Basically I want to use uniqueidentifier in similar way as identity. I don\'t want to insert values into it, It should just insert values automatically, different value for

Answer 1

Or even better: use the newsequentialid() as the default for your UNIQUEIDENITIFER column. That'll give you a somewhat sequential series of GUIDs.

CREATE TABLE dbo.YourTable   
   (SerialID UNIQUEIDENTIFIER 
        CONSTRAINT DF_SerialID DEFAULT newsequentialid(),
     .... (other columns)......
   )

Trouble is: newsequentialid is only available as a column default - you cannot call it as a function or anything. But that seems to fit your requirements.

UPDATE: there appears to be an acknowledged bug in SQL Server Management Studio that prevents specifying newsequentialid() as the default for a column in the interactive table designer.

See: http://social.msdn.microsoft.com/Forums/en-US/sqltools/thread/cad8a4d7-714f-44a2-adb0-569655ac66e6

Workaround: create your table without specifying any default, and then type in this T-SQL statement in a normal query window and run it:

ALTER TABLE dbo.YourTable
    ADD CONSTRAINT DF_SerialID DEFAULT newsequentialid() FOR SerialID

That should do the trick!

Answer 2

Use NewID() as the default value. At least this is what you would do for SQL Server.

Answer 3

I think

CREATE TABLE dbo.YourTable
(
    SerialID UNIQUEIDENTIFIER PRIMARY KEY DEFAULT newsequentialid()
)

is simplier

Answer 4

I guess you mean in SQLServer and not C#...

Set the column as PRIMARY KEY and ROWGUID

RowGuid http://img341.imageshack.us/img341/8867/sqlserverrowguid.png