Answer by Priyanka Vadhwani for Add a column with a default value to an existing table in SQL Server

SYNTAX:

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

EXAMPLE:

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