BEGIN;
CREATE TABLE foo (
  foo_id SERIAL PRIMARY KEY
);

CREATE TABLE parent (
  parent_id SERIAL PRIMARY KEY
, foo_id INTEGER NOT NULL REFERENCES foo(foo_id) ON DELETE CASCADE
, parent_1_text TEXT NOT NULL
);

CREATE TABLE child_1 (
  child_1_text TEXT NOT NULL
) INHERITS(parent);

CREATE TABLE child_2 (
  child_2_text TEXT NOT NULL
) INHERITS(parent);

INSERT INTO foo VALUES(DEFAULT);
INSERT INTO child_1 (foo_id, parent_1_text, child_1_text)
VALUES (currval('public.foo_foo_id_seq'), 'parent text 1', 'child_1 text 1');

INSERT INTO foo VALUES(DEFAULT);
INSERT INTO child_1 (foo_id, parent_1_text, child_1_text)
VALUES (currval('public.foo_foo_id_seq'), 'parent text 2', 'child_1 text 2');

INSERT INTO foo VALUES(DEFAULT);
INSERT INTO child_2 (foo_id, parent_1_text, child_2_text)
VALUES (currval('foo_foo_id_seq'), 'parent text 3', 'child_2 text 1');

DELETE FROM foo WHERE foo_id = 1;
SELECT * FROM parent;
SELECT * FROM child_1;
ROLLBACK;