Using a Named Sequence with an AUTO_INCREMENT or IDENTITY Column

A table can contain only one AUTO_INCREMENT or IDENTITY column. A table with an AUTO_INCREMENT or IDENTITY column can also contain a named sequence. In the following example, table test2 contains a named sequence (my_seq), and an auto_increment value for the column last):

VMart=> CREATE TABLE test2 (id INTEGER NOT NULL UNIQUE, 
  middle INTEGER DEFAULT NEXTVAL('my_seq'), 
  next INT, last AUTO_INCREMENT);
CREATE TABLE