如何在SQL中分組多個聚合結果

Question

我有一個查詢返回用戶所在的ID，最高值和最高級別的項目。

我的查詢如下：

SELECT id, 
MAX(item) AS highest_item, 
MAX(level) AS highest_level 
FROM data 
GROUP BY 1 
ORDER BY 1; 

我如何可以查詢數據庫，這樣我收到的唯一用戶的總數，誰是在同一水平最高，並且具有相同價值最高的項目嗎？

Answer 1

您可以根據您需要的值獲得計數（distcint id）。例如。對於這兩個值：

select count(distinct id), highest_item, highest_level 

    from ( 
    SELECT id, 
    MAX(item) AS highest_item, 
    MAX(level) AS highest_item 
    FROM data 
    GROUP BY 1 
) t 
group by highest_item, highest_level 
order by count(distinct id) desc 

或highest_item

select count(distinct id), highest_item 

    from ( 
    SELECT id 
    MAX(item) AS highest_item, 
    MAX(level) AS highest_level 
    FROM data 
    GROUP BY 1 
) t 
group by highest_item 
order by count(distinct id) desc 

的

爲HIGHEST_LEVEL

select count(distinct id), highest_level 

    from ( 
    SELECT id, 
    MAX(item) AS highest_item, 
    MAX(level) AS highest_level 
    FROM data 
    GROUP BY 1 
) t 
group by highest_level 
order by count(distinct id) desc 

Answer 2

你可以試試這個也

Select id,count(Id) from data group by level,item having level=max(level) and item=max(item)