Question

我不知道如何实现这一点。

我的数据库中有2个表：

表1：轮次

+------------+----------+---------+----------+---------------+
|  round_id  |  format  |  Size   |  poster  | tournament_id |
+------------+----------+---------+----------+---------------+
|     6      |  Single  |   12    |  Luis    |      1
|     7      |  Single  |   9     |  Daniel  |      1        |
|     8      |  Single  |   4     |  Oscar   |      1        |
+------------+----------+---------+----------+---------------+

表2：匹配

+------------+----------+-------------+----------+----------+
|  round_id  |  player  |  position   |  score   |  winner  |
+------------+----------+-------------+----------+----------+
|     6      |  Doris   |     0       |    1     |    1     |
|     7      |  Arturo  |     0       |    3     |    1     |
|     7      |  Pablo   |     1       |    2     |    0     |
|     8      |  Ale     |     0       |    1     |    0     |
|     8      |  Maria   |     1       |    5     |    1     |
|     8      |  Roberto |     2       |    4     |    0     |
+------------+----------+-------------+----------+----------+

在第一桌我有几轮比赛，在第二桌有每轮比赛，因为你可以看到一轮中的每场比赛有不同规模的球员。所以我想获得轮次的所有信息 BUT 只是表格中的最后两轮＆＃34;轮次＆＃34;，在一个查询中得到类似的内容：

查询结果：

//主键可以是round_id或0到n的数字 //

[7] => Array
    (
        ['poster'] => 'Daniel'
        ['format'] => 'single'

            (
                [0] => Array
                      (
                          ['player'] => 'Arturo'
                          ['score'] => 3
                       )
                [1] => Array
                       (
                          ['player'] => 'Pablo'
                          ['score'] => 2
                       )
            )

    )
[8] => Array
    (
        ['poster'] => 'Oscar'
        ['format'] => 'single'

            (
                [0] => Array
                      (
                          ['player'] => 'Ale'
                          ['score'] => 1
                       )
                [1] => Array
                       (
                          ['player'] => 'Maria'
                          ['score'] => 5
                       )
                [2] => Array
                       (
                          ['player'] => 'Roberto'
                          ['score'] => 4
                       )
            )

    )

因此，在我的页面中，我可以显示上传的最后一轮，如下所示：

+---------------------------+
|  by Daniel                |
|  Arturo (3) vs Pablo (2)  |
+---------------------------+

+---------------------------------------+      
|  by Oscar                             |
|  Ale (1) vs Maria (5) vs Roberto (4)  |
+---------------------------------------+

希望MySQL专家可以帮助我：）

Answer 1

使用子查询加入matches表，该子查询获取rounds表中的最后两行。

SELECT *
FROM (SELECT *
      FROM rounds
      ORDER BY round_id DESC
      LIMIT 2) AS r
JOIN matches AS m ON r.round_id = m.round_id

请参阅Creating one array from another array in php，了解如何组合PHP数组中同一轮的匹配信息。

如果您希望查询每轮返回一行，您可以使用GROUP_CONCAT将match信息合并到一个列中：

SELECT r.poster, r.format, GROUP_CONCAT(CONCAT(m.player, '(', m.score, ')') SEPARATOR ' vs ') AS players
FROM (SELECT round_id, poster, format
      FROM rounds
      ORDER BY round_id DESC
      LIMIT 2) AS r
JOIN matches AS m ON r.round_id = m.round_id
GROUP BY m.round_id

查询显示最近2轮锦标赛的比赛信息

1 个答案: