Forward declaration of table - Mailing list pgsql-general

From Alexander Farber
Subject Forward declaration of table
Date
Msg-id CAADeyWgH7ywQBVpw_cLHbcB5Q_9XMsvvEuUSa5OebKzEwDyaVQ@mail.gmail.com
Whole thread Raw
Responses Re: Forward declaration of table  (Adrian Klaver <adrian.klaver@aklaver.com>)
Re: Forward declaration of table  ("David G. Johnston" <david.g.johnston@gmail.com>)
Re: Forward declaration of table  (Igor Neyman <ineyman@perceptron.com>)
List pgsql-general
Good evening,

with PostgreSQL 9.5.3 I am using the following table to store 2-player games:

DROP TABLE IF EXISTS words_games;
CREATE TABLE words_games (
        gid SERIAL PRIMARY KEY,
        created timestamptz NOT NULL,
        player1 integer REFERENCES words_users(uid) ON DELETE CASCADE NOT NULL,
        player2 integer REFERENCES words_users(uid) ON DELETE CASCADE,
        played1 timestamptz,
        played2 timestamptz,
        -- mid1 integer REFERENCES words_moves(mid) ON DELETE CASCADE,
        -- mid2 integer REFERENCES words_moves(mid) ON DELETE CASCADE,
        score1 integer NOT NULL CHECK(score1 >= 0),
        score2 integer NOT NULL CHECK(score2 >= 0),
        hand1 varchar[7] NOT NULL,
        hand2 varchar[7] NOT NULL,
        pile  varchar[116] NOT NULL,
        letters varchar[15][15] NOT NULL,
        values integer[15][15] NOT NULL,
        bid integer NOT NULL REFERENCES words_boards ON DELETE CASCADE
);

This has worked well for me (when a user connects to the game server, I send her all games she is taking part in), but then I have decided to add another table to act as a "logging journal" for player moves:

DROP TABLE IF EXISTS words_moves;

DROP TYPE IF EXISTS words_action;

CREATE TABLE words_moves (
        mid SERIAL PRIMARY KEY,
        action words_action NOT NULL,
        gid integer NOT NULL REFERENCES words_games ON DELETE CASCADE,
        uid integer NOT NULL REFERENCES words_users ON DELETE CASCADE,
        played timestamptz NOT NULL,
        tiles jsonb,
        score integer CHECK(score > 0)
);

Also, in the former table words_games I wanted to add references to the latest moves performed by players:

        -- mid1 integer REFERENCES words_moves(mid) ON DELETE CASCADE,
        -- mid2 integer REFERENCES words_moves(mid) ON DELETE CASCADE,

The intention is: whenever a player connects to the server, sent her all active games and status updates on the recent opponent moves.

However the 2 added columns do not work:

ERROR:  relation "words_moves" does not exist
ERROR:  relation "words_games" does not exist
ERROR:  relation "words_moves" does not exist

So my question is if I can somehow "forward declare" the words_moves table?

Here are all tables of my game for more context: 

Thank you
Alex

pgsql-general by date:

Previous
From: Francisco Olarte
Date:
Subject: Re: Sequential vs. random values - number of pages in B-tree
Next
From: Adrian Klaver
Date:
Subject: Re: Forward declaration of table