Re: Displaying chat by punished users only to themselves (db fiddle attached)

["David G. Johnston" <david.g.johnston@xxxxxxxxx>]

On Thursday, May 5, 2022, Alexander Farber <alexander.farber@xxxxxxxxx> wrote:

Good evening, I still have a problem with my JOIN _expression_ -

when I add more games, then messages from other games are displayed:

https://dbfiddle.uk/?rdbms=postgres_14&fiddle=e2ff211f59090d1eeab879498148f907

CREATE OR REPLACE FUNCTION words_get_chat(
                in_gid   integer,
                in_uid   integer
        ) RETURNS TABLE (
                out_mine integer,
                out_game text,
                out_msg  text
        ) AS
$func$
        SELECT
                CASE WHEN c.uid = in_uid THEN 1 ELSE 0 END,
                'game #' || c.gid,
                c.msg
        FROM    words_chat c
        JOIN    words_games g USING (gid)
        JOIN    words_users opponent ON (opponent.uid IN (g.player1, g.player2) AND opponent.uid <> in_uid)
        WHERE   c.gid = in_gid
        -- always show myself my own chat messages
        AND     c.uid = in_uid
        -- otherwise only show messages by not muted opponents
        OR      NOT opponent.muted
        ORDER BY c.created ASC;

$func$ LANGUAGE sql;

I have tried making the JOIN words_users opponent even more restrictive with:

        JOIN    words_users opponent ON (opponent.uid IN (g.player1, g.player2) AND in_uid IN (g.player1, g.player2) AND opponent.uid <> in_uid)

but still messages from the game #20 are displayed, even though I pass in_gid = 10

You want:  gid and (uid or muted); what you have is: (gid and uid) or muted; based upon operator precedence.

David J.