DEFAULT Constraints

To supply a value (when a user does not enter one in a column), define a DEFAULT constraint or a default on the column. DEFAULT constraints are defined with the CREATE TABLE or ALTER TABLE statement. Defaults are created with the CREATE DEFAULT statement and bound with the sp_bindefault system stored procedure. Unlike defaults, DEFAULT constraints do not need a separate binding step.

When you insert a row with the INSERT statement, you can specify default values for one or all columns in the row by using the DEFAULT or DEFAULT VALUES options.

    To create a DEFAULT constraint

• In SQL Enterprise Manager's Server Manager window, double-click the appropriate table, choose the Advanced Features button, and then enter the appropriate default in the Default column.

  (For details, search for "constraints" in SQL Enterprise Manager Help.)

Or

• Use the CREATE TABLE or ALTER TABLE statement.

  For example:

  ALTER TABLE authors
  ADD
  DEFAULT 'UNKNOWN' for au_frame

  add the word "UNKNOWN" anytime no entry is made in the au_frame column.

  (For details, see the CREATE TABLE and ALTER TABLE statements in the Microsoft SQL Server Transact-SQL Reference.)

For details on INSERT, see the INSERT statement in the Microsoft SQL Server Transact-SQL Reference.