Question

我有这样的数据集 -

**Team  Date    W/L**
Team_1  04/01/0012  W
Team_1  06/01/0012  W
Team_1  07/01/0012  L
Team_1  14/01/0012  W
Team_1  19/01/0012  W
Team_1  30/01/0012  L
Team_1  14/02/0012  W
Team_1  17/02/0012  L
Team_1  20/02/0012  W
Team_2  01/01/0012  W
Team_2  05/01/0012  W
Team_2  09/01/0012  W
Team_2  13/01/0012  L
Team_2  18/01/0012  W
Team_2  25/01/0012  L
Team_2  05/02/0012  L
Team_2  13/02/0012  L
Team_2  19/02/0012  L
Team_3  02/01/0012  W
Team_3  02/01/0012  W
Team_3  06/01/0012  W
Team_3  10/01/0012  W
Team_3  19/01/0012  W
Team_3  31/01/0012  L
Team_3  11/02/0012  W
Team_3  15/02/0012  L
Team_3  21/02/0012  W

由此我需要找出谁拥有最大的连续胜利 -

团队计数

Team_3  5
Team_2  3
Team_1  2

我被允许只写sql查询。我怎么写这个？

Answer 1

您可以使用以下内容：

SELECT  Team, TotalWins, FirstWin, LastWin
FROM    (   SELECT  Team, 
                    WL,
                    COUNT(*) TotalWins,
                    MIN("Date") FirstWin,
                    MAX("Date") LastWin,
                    ROW_NUMBER() OVER(PARTITION BY Team, WL ORDER BY COUNT(*) DESC) RowNumber
            FROM    (   SELECT  Team,
                                "Date",
                                WL, 
                                ROW_NUMBER() OVER(PARTITION BY Team ORDER BY "Date") - ROW_NUMBER() OVER(PARTITION BY Team, WL ORDER BY "Date") Grouping
                        FROM    T
                    ) GroupedData
            WHERE   WL = 'W'
            GROUP BY Team, WL, Grouping
        ) RankedData
WHERE   RowNumber = 1;

它使用ROW_NUMBER对按团队划分的每个游戏进行排名，并且还通过结果，这两者之间的差异对于每组连续结果是唯一的。所以对于你的第一支队伍你会有：

Team    Date        W/L RN1     RN2 DIFF
Team_1  04/01/0012  W   1       1   0
Team_1  06/01/0012  W   2       2   0
Team_1  07/01/0012  L   3       1   2
Team_1  14/01/0012  W   4       3   1
Team_1  19/01/0012  W   5       4   1
Team_1  30/01/0012  L   6       2   4
Team_1  14/02/0012  W   7       5   2
Team_1  17/02/0012  L   8       3   5
Team_1  20/02/0012  W   9       6   3

RN1只是由团队划分，而rn2是按团队划分的结果。

正如您所看到的，如果您删除了损失，那么DIFF列会为每组连续胜利增加1：

Team    Date        W/L RN1     RN2 DIFF
Team_1  04/01/0012  W   1       1   0
Team_1  06/01/0012  W   2       2   0
---------------------------------------
Team_1  14/01/0012  W   4       3   1
Team_1  19/01/0012  W   5       4   1
---------------------------------------
Team_1  14/02/0012  W   7       5   2
---------------------------------------
Team_1  20/02/0012  W   9       6   3

然后，您可以按此分组，以确保您正在查看连续获胜，并进行计数以获得最大收益。然后我就用另一个rownumber来获得每队最大的连续胜利。

<强> Example on SQL Fiddle

分组和计数

1 个答案: