codekingpro/portable-devtools

1DROP SEQUENCE next_id;2DROP TABLE ids;3 4CREATE SEQUENCE next_id START -2 MINVALUE -2;5 6CREATE TABLE ids (7	id		int4,8	idesc		text9);10 11CREATE TRIGGER ids_nextid12	BEFORE INSERT OR UPDATE ON ids13	FOR EACH ROW14	EXECUTE PROCEDURE autoinc (id, next_id);15 16INSERT INTO ids VALUES (0, 'first (-2 ?)');17INSERT INTO ids VALUES (null, 'second (-1 ?)');18INSERT INTO ids(idesc) VALUES ('third (1 ?!)');19 20SELECT * FROM ids;21 22UPDATE ids SET id = null, idesc = 'first: -2 --> 2'23	WHERE idesc = 'first (-2 ?)';24UPDATE ids SET id = 0, idesc = 'second: -1 --> 3'25	WHERE id = -1;26UPDATE ids SET id = 4, idesc = 'third: 1 --> 4'27	WHERE id = 1;28 29SELECT * FROM ids;30 31SELECT 'Wasn''t it 4 ?' as nextval, nextval ('next_id') as value;32 33insert into ids (idesc) select textcat (idesc, '. Copy.') from ids;34 35SELECT * FROM ids;36