使用CTE對查詢結果進行分組

Question

我有一個基於CTE的查詢，在其中傳遞了大約2600個4元組的緯度/經度值-這些值已ID標記並保存在稱為坐標的第二個表中。 這些左上和右下的緯度/經度值傳遞到CTE中，以顯示在給定的兩個時間戳下這些坐標內發出的請求數量（每小時）。

但是，我想在給定的時間戳內每天獲取總請求數。 也就是說，我想獲取每個指定日期的用戶請求總數。 例如，用戶選擇在我經過的每個緯度/經度4元組中查看每個星期三或星期三以及星期四等-在2012年1月1日至16日之間的11:55到22:04之間。 輸出基本上是這樣的：

coordinates_id | stamp       | zcount

1                Jan 4 2012    200 (total requests on Wednesday Jan 4 between 11:55 and 22:04)
1                Jan 11 2012   121 (total requests on Wednesday Jan 11 between 11:55 and 22:04)
2                Jan 4 2012    255 (total requests on Wednesday Jan 4 between 11:55 and 22:04)
2                Jan 11 2012   211 (total requests on Wednesday Jan 11 between 11:55 and 22:04)
.
.
.

我該怎么做？ 我的查詢如下：

WITH v AS (
   SELECT '2012-01-1 11:55:11'::timestamp AS _from -- provide times once
         ,'2012-01-16 22:02:21'::timestamp AS _to
   )
, q AS (
   SELECT c.coordinates_id
        , date_trunc('hour', t.calltime) AS stamp
        , count(*) AS zcount
   FROM   v
   JOIN   mytable t ON  t.calltime BETWEEN v._from AND v._to
                   AND (t.calltime::time >= v._from::time AND
                        t.calltime::time <= v._to::time) AND 
(extract(DOW from t.calltime) = 3)
   JOIN   coordinates c ON (t.lat, t.lon) 
                   BETWEEN (c.bottomrightlat, c.topleftlon)
                       AND (c.topleftlat, c.bottomrightlon)
   GROUP BY c.coordinates_id, date_trunc('hour', t.calltime)
   )
, cal AS (
   SELECT generate_series('2011-2-2 00:00:00'::timestamp
                        , '2012-4-1 05:00:00'::timestamp
                        , '1 hour'::interval) AS stamp
   FROM v
   )
SELECT q.coordinates_id, cal.stamp, COALESCE (q.zcount, 0) AS zcount
FROM v, cal
LEFT JOIN q USING (stamp)
WHERE (extract(hour from cal.stamp) >= extract(hour from v._from) AND
       extract(hour from cal.stamp) <= extract(hour from v._to)) AND 
(extract(DOW from cal.stamp) = 3)
       AND cal.stamp >= v._from AND cal.stamp <= v._to
GROUP BY q.coordinates_id, cal.stamp, q.zcount
ORDER BY q.coordinates_id ASC, stamp ASC;

它產生的樣本結果是這樣的：

coordinates_id  | stamp                | zcount
1                 2012-01-04 16:00:00    1
1                 2012-01-04 19:00:00    1
1                 2012-01-11 14:00:00    1
1                 2012-01-11 17:00:00    1
1                 2012-01-11 19:00:00    1
2                 2012-01-04 16:00:00    1

因此，如上所述，我希望看到

coordinates_id  | stamp      | zcount
1                2012-01-04    2
1                2012-01-11    3
2                2012-01-04    1

Answer 1

將最終的SELECT更改為：

SELECT q.coordinates_id, cal.stamp::date, sum(q.zcount) AS zcount
FROM   v, cal
LEFT   JOIN q USING (stamp)
WHERE  extract(hour from cal.stamp) BETWEEN extract(hour from v._from)
                                        AND extract(hour from v._to)
AND    extract(DOW from cal.stamp) = 3 
AND    cal.stamp >= v._from
AND    cal.stamp <= v._to
GROUP  BY 1,2
ORDER  BY 1,2;

將cal.stamp為日期的關鍵部分： cal.stamp::date 。
那和sum(q.zcount) 。