ALTER TABLE <table name> 
ADD <new column name> <data type> NOT NULL
GO
ALTER TABLE <table name> 
ADD CONSTRAINT <constraint name> DEFAULT <default value> FOR <new column name>
GO

添加可为空的列时，WITH VALUES将确保将特定的DEFAULT值应用于现有行：

ALTER TABLE table
ADD column BIT     -- Demonstration with NULL-able column added
CONSTRAINT Constraint_name DEFAULT 0 WITH VALUES

语法：

ALTER TABLE {TABLENAME} 
ADD {COLUMNNAME} {TYPE} {NULL|NOT NULL} 
CONSTRAINT {CONSTRAINT_NAME} DEFAULT {DEFAULT_VALUE}
WITH VALUES

例子：

ALTER TABLE Admin_Master 
ADD Can_View_Password  BIT NULL 
CONSTRAINT DF_Admin_Master_Can_View_Password DEFAULT (1)
WITH VALUES 

--Adding Value with Default Value
ALTER TABLE TestTable
ADD ThirdCol INT NOT NULL DEFAULT(0)
GO

ALTER TABLE MYTABLE ADD MYNEWCOLUMN VARCHAR(200) DEFAULT 'SNUGGLES'

这可以通过以下代码完成。

CREATE TABLE TestTable
    (FirstCol INT NOT NULL)
    GO
    ------------------------------
    -- Option 1
    ------------------------------
    -- Adding New Column
    ALTER TABLE TestTable
    ADD SecondCol INT
    GO
    -- Updating it with Default
    UPDATE TestTable
    SET SecondCol = 0
    GO
    -- Alter
    ALTER TABLE TestTable
    ALTER COLUMN SecondCol INT NOT NULL
    GO