Modifying Tables
You can use an ALTER TABLE statement to modify a table definition after creating the table. ALTER TABLE statements allow you to add or drop columns; add or drop primary and foreign keys; and change the pathname of a table’s data file.
The following example adds a numeric column called Emergency_Phone to the Tuition table in the sample database.
ALTER TABLE Tuition ADD Emergency_Phone NUMERIC(10,0)#
For more information about columns, refer to Chapter
14
,
Inserting and Deleting Data
. For more information about primary and foreign keys, refer to Chapter
18
,
Managing Data