Sql 如何运行此查询？

我有下表

MID IID

1   23

1   24

1   25

2   32

2   54

3   11

4   55

5   67

我想找到所有的MID，其中计数（IID）>1 i、 e结果如下

MID count(IID)

1   3

2   2

另外，我试过了，但是我在所有的中期测试中都得到了结果。这是我的问题

select distinct a.MID,count(a.IID) from Item_attribute as a group by a.MID

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添加如下条款：

having count(a.IID)>1

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在SELECT语句中使用HAVING子句：

SELECT a.MID,count(a.IID) 
FROM Item_attribute as a 
GROUP BY a.MID
HAVING COUNT(a.IID) > 1

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请尝试以下方法

SELECT MID,
       COUNT( IID ) as CountIID
    FROM Item_attribute
    GROUP BY MID
HAVING COUNT( IID ) > 1;

SELECT MID,
       CountIID
FROM
(
    SELECT MID,
           COUNT( IID ) as CountIID
    FROM Item_attribute
    GROUP BY MID
    HAVING COUNT( IID ) > 1
) AS limitedCountIIDFinder
WHERE CountIID =  ( SELECT MAX( CountIID ) AS MaxCountIID
                    FROM
                    (
                        SELECT MID,
                               COUNT( IID ) as CountIID
                        FROM Item_attribute
                        GROUP BY MID
                    ) AS countIIDFinder
                  )

对于其他查询，请尝试以下操作

SELECT MID,
       COUNT( IID ) as CountIID
    FROM Item_attribute
    GROUP BY MID
HAVING COUNT( IID ) > 1;

SELECT MID,
       CountIID
FROM
(
    SELECT MID,
           COUNT( IID ) as CountIID
    FROM Item_attribute
    GROUP BY MID
    HAVING COUNT( IID ) > 1
) AS limitedCountIIDFinder
WHERE CountIID =  ( SELECT MAX( CountIID ) AS MaxCountIID
                    FROM
                    (
                        SELECT MID,
                               COUNT( IID ) as CountIID
                        FROM Item_attribute
                        GROUP BY MID
                    ) AS countIIDFinder
                  )

（后面的解释…）

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如果您有任何问题或意见，请随时发表相应的意见。

如果您希望对聚合字段设置条件，您需要使用

having

如果使用分组方式，也不需要使用distinct。
就你而言：

select a.MID,count(a.IID) from Item_attribute as a group by a.MID having count(a.IID)>1 

如果要获取“最大计数”值，请按降序对其进行排序，并获取前1：

select top 1 a.MID,count(a.IID) 
from Item_attribute as a 
group by a.MID 
having count(a.IID)>1 
order by count(a.IID) desc

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添加如下having子句：“having count（a.IID）>1”是的，它起作用了……谢谢！还有一件事…如果我必须只找到包含最大值（计数（iid））的MID呢？谢谢。。还有一件事，如果我必须只找到包含max（count（iid））的MID，该怎么办？我已经更新了我的答案，以包含一个查询，该查询将完成这项工作。它会给你所有顶级国家的记录。如果你只想要一个，选择哪一个重要吗？