Postgres 16

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create table public."Booking"(
  "Id" int generated by default as identity primary key);
insert into public."Booking" values (default),(default),(default)
  returning *;

CREATE TABLE

Id

1

2

3

INSERT 0 3

alter table public."Booking" drop column if exists "LinkedBookings";
alter table public."Booking" add column "LinkedBookings" int[];
update public."Booking" b set "LinkedBookings" = ('{'||"Id"::text||'}')::int[]
  returning *,pg_typeof("LinkedBookings");

ALTER TABLE

ALTER TABLE

Id
LinkedBookings
pg_typeof

1
{1}
integer[]

2
{2}
integer[]

3
{3}
integer[]

UPDATE 3

update public."Booking" b set "LinkedBookings" = (ARRAY["Id"])::int[]
  returning *,pg_typeof("LinkedBookings");

Id
LinkedBookings
pg_typeof

1
{1}
integer[]

2
{2}
integer[]

3
{3}
integer[]

UPDATE 3

alter table public."Booking" drop column if exists "LinkedBookings";
alter table public."Booking" add column "LinkedBookings" int[] 
   generated always as ((ARRAY["Id"])::int[]) stored;
--no update necessary
select *,pg_typeof("LinkedBookings") from public."Booking";

ALTER TABLE

ALTER TABLE

Id
LinkedBookings
pg_typeof

1
{1}
integer[]

2
{2}
integer[]

3
{3}
integer[]

SELECT 3