Creating, Altering, and Removing Defaults

In SQL Server Management Objects (SMO), the default constraint is represented by the Default object.

The TextBody property of the Default object is used to set the value to be inserted. This can be a constant or a Transact-SQL statement that returns a constant value, such as GETDATE(). The TextBody property cannot be modified by using the Alter method. Instead, the Default object must be dropped and re-created.