Question

我正在制作一个程序，根据具有两个属性得分的最高总和的人自动建议选择哪个玩家，例如，得分和等级。目标得救。因此，我有一个表（玩家），看起来像这样：

+---------------+--------------+-------------+
|     Name      | GoalsScored  | GoalsSaved  |
+---------------+--------------+-------------+
| John Smith    |           15 |          12 |
| John Doe      |           12 |          20 |
| Bob John      |            7 |           6 |
| John Bob      |           10 |          30 |
| Bobby Johnson |           25 |          30 |
+---------------+--------------+-------------+

一个临时表来存储已经选择的玩家（taken_players）的名字，看起来像这样：

+-----------------+
| takenplayername |
+-----------------+
| Bob John        |
| Bobby Johnson   |
+-----------------+

我正在寻找返回具有最高GoalsScored + GoalsSaved的玩家名称的SQL查询，只要该玩家未列在所拍摄玩家的表中。

SELECT * FROM players 
LEFT JOIN taken_players ON players.Name = taken_players.takenplayername 
WHERE taken_players.takenplayername IS NULL 
  AND GoalsScored, GoalsSaved in (
        SELECT MAX(GoalsScored + GoalsSaved) 
        FROM players
  )

到目前为止，我有上面的代码，只能部分工作。我遇到的问题是

GoalsScored, GoalsSaved in (SELECT MAX(GoalsScored + GoalsSaved)

声明的一部分没有做我需要的，我在这里猜测一些代码来说明我希望它为此问题的目的做什么。

另一个问题是，如果将最佳玩家添加到所选玩家列表中，则查询将返回任何内容而不是下一个最佳玩家。

我对此很新，任何帮助都将不胜感激。

Answer 1

您希望order by和某些内容限制为一行：

SELECT p.*
FROM players p LEFT JOIN
     taken_players tp
     ON p.Name = tp.takenplayername
WHERE tp.takenplayername IS NULL
ORDER BY (GoalsScored + GoalsSaved) DESC
LIMIT 1;

LIMIT 1可能是其他一些因素，具体取决于数据库：

SELECT TOP 1
WHERE rownum = 1
FETCH FIRST 1 ROW ONLY

Answer 2

问题是你的WHERE子句。它将选择最大总和，但它不与特定玩家绑定。解决这个问题的方法之一：

SELECT p.* FROM players p  
LEFT JOIN taken_players t ON p.Name = t.takenplayername 
WHERE t.takenplayername IS NULL
AND (p.GoalsScored + p.GoalsSaved)  = (SELECT MAX(GoalsScored + GoalsSaved) as MaxScore FROM players)

注意：如果多个玩家获得最高分（如果是平局），此查询将返回多个记录

Answer 3

SELECT * from players p where p.id not in (SELECT id from taken_players) and (p.GoalsScored + p.GoalsSaved) = (SELECT MAX(GoalsScored + GoalsSaved) as MaxScore FROM players)

与上述答案类似，它可能会为您提供多个玩家。只获得一个玩家的语法因DBMS而异，但这在大多数情况下都有效。

SELECT * FROM Players where id = (SELECT MIN(id) from players where players.id NOT in (SELECT id from taken_players) and players.GoalsScored+ players.GoalsSaved = (SELECT MAX(players.GoalsScored+ players.GoalsSaved from players where players.id not in (SELECT id from taken_players))

如何返回具有两列最高总和的行？

3 个答案: