问题
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 each row. I'm not able to set autoincrement on columns of type uniqueidentifier(the property 'autoincrement' is set to false and is not editable).
回答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!
回答2:
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
回答3:
Use NewID() as the default value. At least this is what you would do for SQL Server.
回答4:
I think
CREATE TABLE dbo.YourTable
(
SerialID UNIQUEIDENTIFIER PRIMARY KEY DEFAULT newsequentialid()
)
is simplier
来源:https://stackoverflow.com/questions/2837559/autoincrement-uniqueidentifier