Question

我在下面列出了我所运行的查询以及预期的和实际的结果。我认为这个问题与WHERE子句中过滤器的组合有关-我希望一个表中的前两个查询的结果基本上是两列。

预期输出：28;实际产量：28

SELECT COUNT(t.Id) 
FROM teams AS t
WHERE teamStatusId = 339 AND live = 1

预期输出：1；实际输出：1

SELECT COUNT(p.Id) 
FROM Players AS p
INNER JOIN teams AS t ON t.TeamId = p.Id
WHERE teamStatusId = 339 AND isInjuired = 1

预期输出28 | 1个实际输出：30 | 30

SELECT 
    COUNT(p.Id) AS 'Players', 
    COUNT(t.Id) AS 'Team'
FROM 
    Players AS p
INNER JOIN
    Teams AS t ON p.TeamId = t.Id 
WHERE
    teamStatusId = 339 
    AND p.isInjuired = 1  
    AND t.live = 1

Answer 1

如果一个球员属于多支球队，那么您的盘点次数将会增加，在这种情况下，您需要在DISTINCT中使用COUNT()：

SELECT COUNT(DISTINCT p.Id) AS 'Players', COUNT(DISTINCT t.Id) AS 'Team'
FROM Players as p INNER JOIN
     Teams t 
     ON p.TeamId = t.Id 
WHERE teamStatusId = 339 AND p.isInjuired = 1 AND t.live = 1;

SQL查询-合并两个表

1 个答案: