Re: Counting booleans in GROUP BY sections

On 11/29/19 8:38 AM, Alexander Farber wrote:
> Good evening,
>
> I am trying to count the booleans per each GROUP BY section by the
> following stored function:
>
> CREATE OR REPLACE FUNCTION words_list_puzzles(
>                 in_start interval,
>                 in_end interval
>
>         ) RETURNS TABLE (
>                 out_label  text,
>                 out_count  bigint,
>                 out_puzzle boolean,
>                 out_mid    bigint,
>                 out_secret text,
>                 out_gid    integer,
>                 out_score  integer
>         ) AS
> $func$
>
>     SELECT
>         TO_CHAR(played, 'Mon YYYY') AS label,
>         COUNT(NULLIF(puzzle, FALSE)), -- this only returns 0 or 1, why?

If I am following it is because you have mid in GROUP BY and mid is a
PK. Since mid will always be unique you will have at most on row per group.

>         puzzle,
>         mid,
>         MD5(mid || ‘my little secret’) AS secret,
>         gid,
>         score
>
>     FROM words_moves
>     WHERE action = 'play'
>     AND LENGTH(hand) = 7
>     AND (LENGTH(letters) = 7 OR score > 90)
>     AND played > CURRENT_TIMESTAMP - in_start
>     AND played < CURRENT_TIMESTAMP - in_end
>     GROUP BY label, puzzle, mid, secret, gid, score
>     ORDER BY played DESC
>
> $func$ LANGUAGE sql STABLE;
>
> But when I run it, I only get 0 or 1 in the out_count column:
>
> words_ru=> select * from words_list_puzzles(interval '2 year', interval
> '1 year');
>  out_label | out_count | out_puzzle | out_mid |            out_secret
>          | out_gid | out_score
> -----------+-----------+------------+---------+----------------------------------+---------+-----------
>  Nov 2018  |         0 | f          | 1326876 |
> e4928d3c34f50b8e6eabf7bad5b932fe |   46007 |        28
>  Nov 2018  |         0 | f          | 1324466 |
> 6228ba509a7124f485feb5c1acbb6b68 |   45922 |        26
>  Nov 2018  |         0 | f          | 1322050 |
> b67b091d383678de392bf7370c735cab |   45877 |        34
>  Nov 2018  |         0 | f          | 1320017 |
> 35f03b0c7159cec070c00aa80359fd42 |   44255 |       120
>  Nov 2018  |         0 | f          | 1319160 |
> 83df42f7ad398bbb060fc02ddfdc62c0 |   45031 |        95
> .....
>  May 2018  |         0 | f          |  264251 |
> 2fff1154962966b16a2996387e30ae7f |   10946 |        99
>  May 2018  |         1 | t          |  257620 |
> 645613db6ea40695dc967d8090ab3246 |   12713 |        93
>  May 2018  |         0 | f          |  245792 |
> bb75bfd9cb443ff541b199d893c68117 |   12359 |        24
>  May 2018  |         1 | t          |  243265 |
> d899a5d642ccd96d931194f48ef56d53 |   11950 |       123
>  May 2018  |         0 | f          |  231953 |
> ad53b5b2c0d4cced3d50e8b44ad53e55 |   11910 |        32
>
> - while I was hoping to get 2 for the "May 2018" section.
>
> What am I doing wrong please, why don't the values add up? Below is the
> table desc:
>
> words_ru=> \d words_moves
>                                       Table "public.words_moves"
>  Column  |           Type           | Collation | Nullable |
>       Default
> ---------+--------------------------+-----------+----------+------------------------------------------
>  mid     | bigint                   |           | not null |
> nextval('words_moves_mid_seq'::regclass)
>  action  | text                     |           | not null |
>  gid     | integer                  |           | not null |
>  uid     | integer                  |           | not null |
>  played  | timestamp with time zone |           | not null |
>  tiles   | jsonb                    |           |          |
>  score   | integer                  |           |          |
>  letters | text                     |           |          |
>  hand    | text                     |           |          |
>  puzzle  | boolean                  |           | not null | false
> Indexes:
>     "words_moves_pkey" PRIMARY KEY, btree (mid)
>     "words_moves_gid_played_idx" btree (gid, played DESC)
>     "words_moves_uid_action_played_idx" btree (uid, action, played)
>     "words_moves_uid_idx" btree (uid)
> Check constraints:
>     "words_moves_score_check" CHECK (score >= 0)
> Foreign-key constraints:
>     "words_moves_gid_fkey" FOREIGN KEY (gid) REFERENCES
> words_games(gid) ON DELETE CASCADE
>     "words_moves_uid_fkey" FOREIGN KEY (uid) REFERENCES
> words_users(uid) ON DELETE CASCADE
> Referenced by:
>     TABLE "words_scores" CONSTRAINT "words_scores_mid_fkey" FOREIGN KEY
> (mid) REFERENCES words_moves(mid) ON DELETE CASCADE
>
> Thank you
> Alex
>

--
Adrian Klaver
adrian(dot)klaver(at)aklaver(dot)com