CREATE OR REPLECE TYPE dateonly	AS OBJECT ( value      DATE
CREATE OR REPLECE TYPE staff__assignment_o  AS OBJECT ( staff_id   NUMBER , start_on   DATEONLY , end_on     DATEONLY , recover at NUMBER
 ,            . ,        ,       ,      .   ,          Oracle   (-)       Oracle.
      .        staff_id,   ,        project_members.  , ,      ,        ,           (  ).
 ,     ,     ,  dateonly       DATE.       :
CREATE TABLE events
( proj_id       NUMBER     NOT NULL REFERENCES projects , event_seq    NUMBER    NOT NULL , primary key (proj_id, event_seq)
, event_code    NUMBER     NOT NULL REFERENCES event__codes , event_date dateonly     NOT NULL ) ;
,        ,     :
INSERT INTO events VALUES (1, 1, 1, dateonly (trunc(sysdate)) ;
 dateonly     -      dateonly.            .   ,  ,   , -      .      event_date   SELECT   WHERE,      -    . :
5. 	101