Adding, Altering, and Dropping a Table Column With SQL

To alter a database object, such as a table, use the SQL ALTER statement, as shown in Example: Adding, Altering, and Dropping a Table Column Using SQL.

Adding, Altering, and Dropping a Table Column Using SQL

-- add a new column
ALTER TABLE personal_info ADD
(contact_email VARCHAR2(30) NULL);

-- modify a column
ALTER TABLE personal_info MODIFY
(contact_email VARCHAR2(40) NOT NULL);

-- drop a column
ALTER TABLE personal_info DROP COLUMN
contact_address;

For information about adding, modifying, and dropping a table column with the Object Browser page, see "Adding a Column To a Table", "Modifying a Column In a Table", and "Dropping a Column From a Table".