PostgreSQL array of elements that each are a foreign key

foreign-collectionforeign-keyspostgresql

I am attempting to create a DB for my app and one thing I'd like to find the best way of doing is creating a one-to-many relationship between my Users and Items tables.

I know I can make a third table, ReviewedItems, and have the columns be a User id and an Item id, but I'd like to know if it's possible to make a column in Users, let's say reviewedItems, which is an integer array containing foreign keys to Items that the User has reviewed.

If PostgreSQL can do this, please let me know! If not, I'll just go down my third table route.

Best Answer

It may soon be possible to do this: https://commitfest.postgresql.org/17/1252/ - Mark Rofail has been doing some excellent work on this patch!

The patch will (once complete) allow

CREATE TABLE PKTABLEFORARRAY (
    ptest1 float8 PRIMARY KEY,
    ptest2 text
);
CREATE TABLE FKTABLEFORARRAY (
    ftest1 int[],
    FOREIGN KEY (EACH ELEMENT OF ftest1) REFERENCES PKTABLEFORARRAY,
    ftest2 int
);

However, author currently needs help to rebase the patch (beyond my own ability) so anyone reading this who knows Postgres internals please help if you can.