HI,
You can try like this:
ALTER TABLE {TABLENAME}
ADD {COLUMNNAME} {TYPE} {NULL|NOT NULL}
CONSTRAINT {CONSTRAINT_NAME} DEFAULT {DEFAULT_VALUE}
Add Default Value to Existing Column
ALTER TABLE [dbo].[Employees] ADD DEFAULT (getdate()) FOR [DateOfHire]
ALTER TABLE [dbo].[Employees] ADD DEFAULT ((0)) FOR [IsTerminated]
Add Default Value with Create Table
CREATE TABLE [dbo].[Employees]
(
[EmployeeID] [INT] IDENTITY(1,1) NOT NULL,
[FirstName] [VARCHAR](50) NULL,
[LastName] [VARCHAR](50) NULL,
[SSN] [VARCHAR](9) NULL,
[IsTerminated] [bit] NOT NULL DEFAULT ((0)) ,
[DateAdded] [datetime] NULL DEFAULT (getdate()),
[Comments] [VARCHAR](255) NULL,
[DateOfHire] [datetime] NULL
)
Hope this will give you some idea...
Thanks