SET SESSION AUTHORIZATION 'dba';

CREATE TABLE ganntinfo (
    id integer NOT NULL,
    seq smallint,
    category character varying(20),
    name character varying(40)
    -- PRIMARY KEY( id, seq )
);

CREATE TABLE taskshead (
    id integer PRIMARY KEY,
    category character varying(20),
    subject character varying(40),
    customer character varying(40),
    description character varying(400)
);

CREATE VIEW tasks (
    id,
    seq,
    category,
    name,
    subject,
    customer,
    description
) AS
  SELECT g.id, g.seq, g.category, g.name, h.subject, h.customer, h.description
  FROM taskshead h LEFT OUTER JOIN ganntinfo g USING ( id, category )
  -- WHERE g.seq = 0 AND g.id = h.id AND g.category = h.category
;

CREATE RULE insert_tasks2taskshead AS
  ON INSERT TO tasks WHERE NEW.seq = 0
  DO (
    insert into taskshead values (
      NEW.id, NEW.category, NEW.subject, NEW.customer, NEW.description
    );
  )
;

CREATE RULE insert_tasks2ganntinfo AS
  ON INSERT TO tasks
  DO INSTEAD (
    insert into ganntinfo values (
      NEW.id, NEW.seq, NEW.category, NEW.name
    );
  )
;

CREATE RULE update_tasks2taskshead AS
  ON UPDATE TO tasks WHERE NEW.seq = 0
  DO NOTHING
;

CREATE RULE update_tasks2ganntinfo AS
  ON UPDATE TO tasks
  DO INSTEAD (
    update ganntinfo set
      id = NEW.id, seq = NEW.seq, category = NEW.category, name = NEW.name
      -- WHERE id = NEW.id AND seq = NEW.seq AND category = NEW.category
    ;
  )
;