Oracle 11g Release 2

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CREATE TYPE address AS OBJECT(
  num    INT,
  street VARCHAR2(20), 
  city   VARCHAR2(20),
  zip INT
);
CREATE TYPE phoneNum AS VARRAY(2) OF VARCHAR2(13);
CREATE TABLE person (
  id            INTEGER
                CONSTRAINT person__id__pk PRIMARY KEY,
  firstName     VARCHAR2(20),
  lastName      VARCHAR2(20),
  date_of_birth DATE,
  adr           address,
  pn            phoneNum
);
CREATE TABLE children(
  id        INTEGER
            CONSTRAINT children__id__pk PRIMARY KEY,
  parent_id CONSTRAINT children__parent_id__fk REFERENCES person (id),
  child_id  CONSTRAINT children__child_id__fk  REFERENCES person (id),
  CONSTRAINT children__pid_cid__u UNIQUE (parent_id, child_id)
);