例子：

ALTER TABLE [Employees] ADD Seniority int not null default 0 GO

ALTER TABLE ADD ColumnName {Column_Type} Constraint

MSDN文章ALTERTABLE（Transact-SQL）具有所有altertable语法。

Use:

-- Add a column with a default DateTime  
-- to capture when each record is added.

ALTER TABLE myTableName  
ADD RecordAddedDate SMALLDATETIME NULL DEFAULT (GETDATE())  
GO 

--Adding New Column with Default Value
ALTER TABLE TABLENAME 
ADD COLUMNNAME DATATYPE NULL|NOT NULL DEFAULT (DEFAULT_VALUE)

OR

--Adding CONSTRAINT And Set Default Value on Column
ALTER TABLE TABLENAME ADD  CONSTRAINT [CONSTRAINT_Name]  DEFAULT 
(DEFAULT_VALUE) FOR [COLUMNNAME]

试试这个

ALTER TABLE Product
ADD ProductID INT NOT NULL DEFAULT(1)
GO

SQL Server+更改表+添加列+默认值uniqueidentifier。。。

ALTER TABLE [TABLENAME] ADD MyNewColumn INT not null default 0 GO