Oracle Tutorial

Alter Table Examples

Example 1

Alter Table contracts
Add approve varchar2(3);

Example 2

Alter Table contracts
Drop column approve;



Example 3

Alter Table customers
Set unused (first_name, last_name);

Example 4

Alter Table customers
add CONSTRAINT fk_user
FOREIGN KEY (user_id, user_name)
REFERENCES user(user_id, user_name)
ON DELETE CASCADE;