Postgres 14

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create table Bookings (
  id bigint not null primary key,
  created_at timestamp default now(),
  start timestamp default now(), 
  product_id bigint,
  UNIQUE (product_id, start) -- add this
);
INSERT INTO Bookings (id,product_id, start) VALUES (1, 111, '2022-05-20 16:39:04');
INSERT INTO Bookings (id,product_id, start) VALUES (2, 145, '2022-05-20 16:39:04');
1 rows affected

1 rows affected

INSERT INTO Bookings (id,product_id, start) VALUES (3, 111, '2022-05-20 16:39:04');
ERROR:  duplicate key value violates unique constraint "bookings_product_id_start_key"
DETAIL:  Key (product_id, start)=(111, 2022-05-20 16:39:04) already exists.


select * from Bookings


id
created_at
start
product_id


1
2022-05-20 16:45:33.340279
2022-05-20 16:39:04
111

2
2022-05-20 16:45:33.340279
2022-05-20 16:39:04
145

id	created_at	start	product_id
1	2022-05-20 16:45:33.340279	2022-05-20 16:39:04	111
2	2022-05-20 16:45:33.340279	2022-05-20 16:39:04	145