Question

我在名为“match_scores”的表格中有以下列：

echo '<pre>';
var_dump($_FILES);
echo '</pre>';

我希望结果是：

<form action="" method="POST" enctype="multipart/form-data">
    <input type="file" id="sell-images" name="images[]" multiple>

    <input type="submit" value="submit">
</form>

Answer 1

你可以＆＃34; univot＆＃34;数据然后重新聚合。在SQL中，这看起来像：

select player, sum(points) as points
from ((select player_1 as player, player_1_points as points from match_scores ms1) union all
      (select player_2 as player, player_2_points as points from match_scores ms2) 
     ) t
group by player;

这将数据作为包含两列的结果集返回。您可以在SQL中转换为字符串，但我真的建议您在应用程序层执行此操作。

Answer 2

这是解决问题的查询：

SELECT DISTINCT (player), sum(points)
FROM (
       SELECT player_1 AS player, player_1_points AS points FROM match_scores
       UNION ALL 
       SELECT player_2 AS player, player_2_points AS points FROM match_scores
     ) AS t
GROUP BY player

所以你注意到的别名放置在最后，只有一个。由于某种原因，在每个选择结尾处放置别名仍然会导致错误

Answer 3

这应该有用..

select player, sum(points) as points
from (select player_1 as player, player_1_points as points 
      from match_scores 
      union all
      select player_2 as player, player_2_points as points 
      from match_scores) as a
group by player;

如何从MySQL表中的两个不同列中获取总和

3 个答案: