Question

**castID**
nm0000116
nm0000116
nm0000116
nm0000116
nm0000116
nm0634240
nm0634240
nm0798899

这是我的表（作为视图创建）。现在我想列出计数最多的castID（在这种情况下是nm0000116，它在这个表中有多少次出现/计数（应该是5次）而且我不太确定要使用哪个查询

Answer 1

SELECT 
  MAX(E),
  castId
FROM 
 (SELECT COUNT(castId) AS E,castId FROM [directors winning movies list] GROUP BY castId) AS t

Answer 2

试

Select CastId, count(*) countOfCastId
From table 
Group By CastId
Having count(*)
    = (Select Max(cnt)
       From (Select count(*) cnt
             From table
             Group By CastId) z)

Answer 3

您可以使用LIMIT返回最顶层的计数：

SELECT   castID,
         COUNT(*) AS Cnt
FROM     atable
GROUP BY castID
ORDER BY Cnt DESC
LIMIT    1
;

但是，如果可以存在关联，则上述查询将只返回一行。如果您想要所有＆＃34;获胜者＆＃34;，您可以将上述查询中的计数作为标量结果，并将其与所有计数进行比较，以仅返回匹配的计数：

SELECT   castID,
         COUNT(*) AS Cnt
FROM     atable
GROUP BY castID
HAVING   COUNT(*) = (
                        SELECT   COUNT(*)
                        FROM     atable
                        GROUP BY castID
                        ORDER BY Cnt DESC
                        LIMIT    1
                    )
;

（基本上与Charles Bretana's approach相同，它只是以不同的方式得出最高计数。）

或者，您可以使用变量对所有计数进行排名，然后仅返回排名为1的计数：

SELECT castID,
       Cnt
FROM   (
          SELECT   castID,
                   COUNT(*) AS Cnt,
                   @r := IFNULL(@r, 0) + 1 AS r
          FROM     atable
          GROUP BY castID
          ORDER BY Cnt DESC
       ) AS s
WHERE r = 1
;

请注意，使用上述方法，变量必须不存在或在运行查询之前使用0或NULL进行预初始化。为安全起见，您可以直接在查询中初始化变量：

SELECT s.castID,
       s.Cnt
FROM   (SELECT @r := 0) AS x
CROSS JOIN
       (
          SELECT   castID,
                   COUNT(*) AS Cnt,
                   @r := @r + 1 AS r
          FROM     atable
          GROUP BY castID
          ORDER BY Cnt DESC
       ) AS s
WHERE s.r = 1
;

如何从表SQL中获取最大计数和ID

3 个答案: