Question

实际上我有以下数据库架构：

* events
id type player match

* players
id name

* matches
id date

事件类型可以是＆＃34; A＆＃34;寻求帮助或＆＃34; G＆＃34;为了目标。我需要在同一个查询中选择两种类型来计算攻击性生产（辅助+目标* 2）。

最终结果必须是：

年球员协助目标off_production

我尝试了以下查询，但它无效（它返回了错误的数据）：

SELECT COUNT(assist.id) AS assistances, COUNT(goals.id) AS goals, (assistances + goals * 2) AS off_prod, p.name AS player, YEAR(m.date) AS year 
FROM matches AS m, players AS p, events AS assist, events AS goals  
WHERE assist.match = m.id AND
assist.type ="A" AND
assist.player = p.id AND 
goals.match = j.id AND 
goals.type ="G" AND
goals.player = p.id
GROUP BY year, player
ORDER BY year DESC, off_prod DESC

提前致谢

Answer 1

试试这个......

SELECT assistances
      ,goals
      ,(A.assistances + A.goals * 2) AS off_prod
      ,player
      ,`YEAR`
FROM (
SELECT COUNT( CASE WHEN e.`type` ='A' THEN 1 ELSE NULL END) AS assistances
      ,COUNT( CASE WHEN e.`type` ='G' THEN 1 ELSE NULL END) AS goals
      ,p.`Name`       AS player
      ,YEAR(m.`date`) AS `year`
FROM       `players`  AS p 
INNER JOIN `events`   AS e     ON p.`id` = e.`player`
INNER JOIN `matches`  AS m     ON e.`match` = m.`id`
GROUP BY p.`name`, YEAR(m.`date`)

) A
ORDER BY A.`year` DESC, (A.assistances + A.goals * 2)  DESC

选择表两次 - 不工作

1 个答案:

`Working Sql Fiddle`