DROP TABLE products CREATE TABLE products( product_no integer NOT NULL, name text, price numeric DEFAULT 200); INSERT INTO products ("product_no", "name") VALUES (1,'pc') ALTER TABLE products ADD UNIQUE (product_no) DELETE from products WHERE name ='pc' INSERT INTO products ("product_no", "name") VALUES (2,'pc') CREATE TABLE orders( order_id integer PRIMARY KEY, product_no integer REFERENCES products (product_no), quantity integer); INSERT INTO orders ("order_id", "product_no", "quantity") VALUES (1,'1', '354') CREATE SEQUENCE lakes_gid_seq; --Apply sequence rules in create table: ALTER TABLE products ALTER product_no SET DEFAULT nextval('tablename_colname_seq'); INSERT INTO products ("name") VALUES ('Ulan') SELECT nextval('tablename_colname_seq') ALTER SEQUENCE tablename_colname_seq RESTART 27; ALTER TABLE "Lakes" ALTER the_geom SET NOT NULL ALTER TABLE "Lakes" ADD CHECK (the_geom IS NOT NULL) --Change sequence ownership to table, so that if delected then sequence is also deleted ALTER SEQUENCE tablename_colname_seq OWNED BY tablename.colname; INSERT INTO tablename(name1) values ('Centuki'), ('derbi'), ('pastoral'); DROP TABLE tablename; -- //get the next value in sequence (nextval...): Select currval('tablename_colname_seq');