Question

我正在制作游戏的排名页面，我希望首先按胜利排序，然后按损失排序（如果人们拥有相同数量的胜利）。以下查询正常工作，以便按顺序按顺序列出一个列表，但我不确定如何将损失放入此查询中。

SELECT username, COUNT(id) AS wins 
  FROM tblBattleHistory 
  WHERE battle_type = '0' && outcome = '1' 
  GROUP BY username 
  ORDER BY wins DESC

结果='1'表示他们赢了，所以当结果='0'时，那意味着他们输了。

Answer 1

你可以这样做：

SELECT username, SUM(outcome) AS wins, COUNT(*) - SUM(outcome) AS losses
  FROM tblBattleHistory 
  WHERE battle_type = '0'
  GROUP BY username 
  ORDER BY wins DESC, losses

Answer 2

这是我的想法：

SELECT username, SUM (CASE WHEN outcome = '1' Then 1 Else 0 End) As Wins,
    SUM (CASE WHEN outcome = '0' Then 1 Else 0 End) As Losses
FROM tblBattleHistory 
WHERE battle_type = '0'
GROUP BY username 
ORDER BY wins DESC, Losses ASC

（根据您的DBMS，您可能必须重复Order By中的SUM而不是使用别名。）

这也允许提出一些陌生人的积分计划，例如德国足球（win = 3，tie = 1分）

SELECT username, SUM (CASE
    WHEN outcome = '1' Then 3 
    WHEN outcome = '2' Then 1 /* 2 is a tie */
    ELSE 0 End) As Points
etc.

Answer 3

这可能也有效：

SELECT
    username,
    SUM(IF(outcome = 1, 1, 0)) AS 'wins',
    SUM(IF(outcome = 0, 1, 0)) AS 'losses'
FROM
    tblBattleHistory;

它基本上计算outcome = 1和outcome = 0的出现次数。

Answer 4

我认为我的答案显然不是你问的问题，但是......我认为你不应该从tblBattleHistory获取计数，你应该向你添加2个文件用户表（胜利，失败）并更新它们（可能通过插入触发器tblBattleHistory）所以你可以通过简单的选择掌握所有数据。

Answer 5

SELECT username, losses, wins
FROM (
    SELECT username, COUNT(id) AS wins 
    FROM tblBattleHistory
    WHERE battle_type = '0' && outcome = '1' 
    GROUP BY username
) A
LEFT JOIN (
    SELECT username, COUNT(id) as losses
    FROM tblBattleHistory
    WHERE battle_type = '0' && outcome = '0'
) B ON A.username = B.username
ORDER BY wins DESC, losses ASC

这可能不是一个有效的查询，但可以胜任。

从MySQL查询中选择2 COUNT（）

5 个答案: