Postgres 13

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CREATE TABLE part (
  part_id serial PRIMARY KEY
, part text NOT NULL
, wide int NOT NULL
, high int NOT NULL
);

CREATE TABLE board (
  board_id serial PRIMARY KEY
, board text NOT NULL
, wide int NOT NULL
, high int NOT NULL
);

-- IMMUTABLE functions:

CREATE OR REPLACE FUNCTION f_boardbox(_board_id int)
  RETURNS box
  LANGUAGE sql IMMUTABLE AS
'SELECT box(point(0,0), point (b.wide, b.high))
 FROM   board b WHERE board_id = $1'; 

CREATE OR REPLACE FUNCTION f_partbox(_part_id int, _wide int, _high int)
  RETURNS box
  LANGUAGE sql IMMUTABLE AS
'SELECT box(point($2,$3), point($2 + p.wide, $3 + p.high))
 FROM   part p WHERE part_id = $1';

-- Main table:

CREATE TABLE board_part (
  board_id int NOT NULL REFERENCES board
, part_id int NOT NULL REFERENCES part
, wide int NOT NULL
, high int NOT NULL
, EXCLUDE USING gist (board_id WITH =, f_partbox(part_id, wide, high) WITH &&)
, CHECK (f_partbox(part_id, wide, high) <@ f_boardbox(board_id))
);
-- Trigger

CREATE OR REPLACE FUNCTION f_board_upaft()
  RETURNS trigger
  LANGUAGE plpgsql AS
$func$
BEGIN
UPDATE  board_part
SET     board_id = board_id       -- enough to trigger CHECK constraint
WHERE   board_id = NEW.board_id;  -- limit to relevant rows

RETURN NULL;
END
$func$;

CREATE TRIGGER board_upaft
AFTER UPDATE OF wide, high ON board  -- limit to relevant columns
FOR EACH ROW EXECUTE PROCEDURE f_board_upaft();


CREATE OR REPLACE FUNCTION f_part_upaft()
  RETURNS trigger
  LANGUAGE plpgsql AS
$func$
BEGIN
UPDATE board_part
SET    part_id = 0
WHERE  part_id = NEW.part_id;

UPDATE board_part
SET    part_id = NEW.part_id
WHERE  part_id = 0;              -- enough to update EXCL. constraint

RETURN NULL;
END
$func$;

CREATE TRIGGER part_upaft
AFTER UPDATE OF wide, high ON part
FOR EACH ROW
EXECUTE PROCEDURE f_part_upaft();
-- Test data:

INSERT INTO board (board, wide, high)
VALUES ('b1010',10,10);

INSERT INTO part (part_id, part, wide, high)
VALUES (0,'p0',0,0);           -- special row needed for trigger!

INSERT INTO part (part, wide, high)
VALUES ('p11',1,1), ('p33',3,3);

INSERT INTO board_part (board_id, part_id, wide, high)
VALUES (1,1,3,3), (1,1,5,5);   -- no overlap, inside board
1 rows affected

1 rows affected

2 rows affected

2 rows affected

TABLE board_part;


board_id
part_id
wide
high


1
1
3
3

1
1
5
5