A sequence is a schema object that can generate unique sequential values. These values are often used for primary and unique keys. One way to populate a key with a value from a sequence is to use a trigger to insert the sequence's
NEXTVAL into the field.
You use the Edit Table dialog to specify that you want to have the primary key for the table populated from a new sequence and updated via a new trigger. On generation of the DDL for the table, both the sequence and the trigger will be generated with no additional coding required.
To open the Edit Table dialog, you will double-click the table in the Application Navigator. You can also open the dialog by choosing
from the context menu.