how to set auto increment column with sql developer

If you want to make your PK auto increment, you need to set the ID column property for that primary key.

1. Right click on the table and select “Edit”.
2. In “Edit” Table window, select “columns”, and then select your PK
   column.
3. Go to ID Column tab and select Column Sequence as Type. This will
   create a trigger and a sequence, and associate the sequence to
   primary key.

See the picture below for better understanding.

// My source is: http://techatplay.wordpress.com/2013/11/22/oracle-sql-developer-create-auto-incrementing-primary-key/