Question

我正在为我们的球队建立一个网站，以获得它的乐趣，并使用PHP和SQL为数据库跟踪统计数据。我通过阅读手册和论坛来学习。我正在构建一个查询，显示当前最长的击球条纹。我偶然发现了一个关于检测运行和条纹的页面，并试图使用它。我对这些东西都很陌生，所以也许我的表格结构不正确。

表“游戏”

+--------+------------+------+
| GameID |    Date    | Time |
+--------+------------+------+
|      1 | 2015/08/19 | 6:30 |
|      2 | 2015/08/20 | 6:30 |
|      3 | 2015/08/22 | 6:30 |
|      4 | 2015/08/24 | 8:00 |
|      5 | 2015/08/24 | 6:30 |
|      6 | 2015/07/15 | 8:00 |
+--------+------------+------+

表“玩家”

+--------+----+---+
| GameID | AB | H |
+--------+----+---+
|      1 |  3 | 1 |
|      2 |  4 | 2 |
|      3 |  2 | 0 |
|      4 |  3 | 0 |
|      5 |  2 | 1 |
|      6 |  3 | 0 |
+--------+----+---+

代码

SELECT games.GameID, GR.H, 
    (SELECT COUNT(*) 
    FROM player G 
    WHERE (CASE WHEN G.H > 0 THEN 1 ELSE 0 END) <> (CASE WHEN GR.H > 0 THEN 1 ELSE 0 END) 
    AND G.GameID <= GR.GameID) as RunGroup 
FROM player GR
INNER JOIN games
ON GR.gameID = games.GameID
ORDER BY Date ASC, Time ASC

基本上为了正确获得正确的连胜，我需要在执行RunGroup部分之前，根据“游戏”表上的日期（ASC）和时间（ASC）对“播放器”表上的GameID进行重新排序代码。显然，通过添加ORDER BY，只有在RunGroup完成查询并导致数据不正确后才能对所有内容进行排序。我已经被困在这里几天了，现在需要一些帮助。

我目前得到的结果是：

+--------+---+----------+
| GameID | H | RunGroup |
+--------+---+----------+
|      6 | 0 |        3 |
|      1 | 1 |        0 |
|      2 | 2 |        0 |
|      3 | 0 |        2 |
|      5 | 1 |        2 |
|      4 | 0 |        2 |
+--------+---+----------+

这就是我想要实现的目标：

+--------+---+----------+
| GameID | H | RunGroup |
+--------+---+----------+
|      6 | 0 |        0 |
|      1 | 1 |        1 |
|      2 | 2 |        1 |
|      3 | 0 |        2 |
|      5 | 1 |        2 |
|      4 | 0 |        3 |
+--------+---+----------+

由于

Answer 1

请考虑以下事项：

DROP TABLE IF EXISTS games;

CREATE TABLE games
(game_id INT NOT NULL AUTO_INCREMENT PRIMARY KEY
,date_played DATETIME NOT NULL
);

INSERT INTO games VALUES
(1,'2015/08/19 18:30:00'),
(2,'2015/08/20 18:30:00'),
(3,'2015/08/22 18:30:00'),
(4,'2015/08/24 20:00:00'),
(5,'2015/08/24 18:30:00'),
(6,'2015/07/15 20:00:00');

DROP TABLE IF EXISTS stats;

CREATE TABLE stats
(player_id INT NOT NULL
,game_id INT NOT NULL
,at_bat INT NOT NULL
,hits INT NOT NULL
,PRIMARY KEY(player_id,game_id)
);

INSERT INTO stats VALUES
(1,1,3,1),
(1,2,4,2),
(1,3,2,0),
(1,4,3,0),
(1,5,2,1),
(1,6,3,0),
(2,1,2,1),
(2,2,3,2),
(2,3,3,0),
(2,4,3,1),
(2,5,2,1),
(2,6,3,0);

SELECT x.*
     , SUM(y.at_bat) runningAB
     , SUM(y.hits) runningH 
     , SUM(y.hits)/SUM(y.at_bat) BA   
  FROM 
     (
       SELECT s.*, g.date_played FROM stats s JOIN games g ON g.game_id = s.game_id
     ) x
  JOIN
     (
       SELECT s.*, g.date_played FROM stats s JOIN games g ON g.game_id = s.game_id
     ) y
    ON y.player_id = x.player_id 
   AND y.date_played <= x.date_played
 GROUP 
    BY x.player_id
     , x.date_played;

+-----------+---------+--------+------+---------------------+-----------+----------+--------+
| player_id | game_id | at_bat | hits | date_played         | runningAB | runningH | BA     |
+-----------+---------+--------+------+---------------------+-----------+----------+--------+
|         1 |       6 |      3 |    0 | 2015-07-15 20:00:00 |         3 |        0 | 0.0000 |
|         1 |       1 |      3 |    1 | 2015-08-19 18:30:00 |         6 |        1 | 0.1667 |
|         1 |       2 |      4 |    2 | 2015-08-20 18:30:00 |        10 |        3 | 0.3000 |
|         1 |       3 |      2 |    0 | 2015-08-22 18:30:00 |        12 |        3 | 0.2500 |
|         1 |       5 |      2 |    1 | 2015-08-24 18:30:00 |        14 |        4 | 0.2857 |
|         1 |       4 |      3 |    0 | 2015-08-24 20:00:00 |        17 |        4 | 0.2353 |
|         2 |       6 |      3 |    0 | 2015-07-15 20:00:00 |         3 |        0 | 0.0000 |
|         2 |       1 |      2 |    1 | 2015-08-19 18:30:00 |         5 |        1 | 0.2000 |
|         2 |       2 |      3 |    2 | 2015-08-20 18:30:00 |         8 |        3 | 0.3750 |
|         2 |       3 |      3 |    0 | 2015-08-22 18:30:00 |        11 |        3 | 0.2727 |
|         2 |       5 |      2 |    1 | 2015-08-24 18:30:00 |        13 |        4 | 0.3077 |
|         2 |       4 |      3 |    1 | 2015-08-24 20:00:00 |        16 |        5 | 0.3125 |
+-----------+---------+--------+------+---------------------+-----------+----------+--------+

Answer 2

我重建了我的数据库，只有一个表来包含所有玩家的统计数据。从那里我能够使用这个查询来找到我对某个玩家最长的当前击球连胜。

SELECT * 
FROM (SELECT (CASE WHEN h > 0 THEN 1 ELSE 0 END) As H, MIN(date_played) as StartDate, 
MAX(date_played) as EndDate, COUNT(*) as Games
FROM (SELECT date_played, (CASE WHEN h > 0 THEN 1 ELSE 0 END) as H, (SELECT COUNT(*) 
FROM stats G WHERE ((CASE WHEN G.h > 0 THEN 1 ELSE 0 END) <> (CASE WHEN GR.h > 0 THEN 1 ELSE 0 END)) 
AND G.date_played <= GR.date_played AND player_id = 13) as RunGroup 
FROM stats GR
WHERE player_id = 13) A
GROUP BY H, RunGroup
ORDER BY Min(date_played)) A
WHERE H = 1
ORDER BY Games DESC 
LIMIT 1

如何从另一个表的列中订购表然后运行查询？

2 个答案: