SQL 服务器：显示字符串多数

Question

我希望在 SQL SERVER 中进行查询，这将允许我在大多数情况下显示在一个分组中的字符串。不是数量，不是最大值，而是大多数情况下显示的字符串：

colA	colB	colC
A	10	ccc
A	20	aaa
A	35	bbb
A	25	aaa
A	10	aaa
B	15	ccc
B	15	bbb
B	30	bbb

Select sum(colB) 作为总数，?????????? 作为标签从表 1 按colA分组

结果：

colA	total	lable
A	100	aaa
B	60	bbb

谢谢！

Answer 1

这是另一种方法

select t.ColA,
       sum(t.total) as ColB,
       max(s2.ColC)
from   ( select s.ColA,
                s.ColC,
                sum(ColB) as total,
                count(1) as numbers
         from   strings s
         group by s.ColA, s.ColC
       ) t  
  outer apply ( select top 1 
                       s.ColA,
                       s.ColC,
                       sum(ColB) as total,
                       count(1) as numbers
                from   strings s
                where  s.ColA = t.ColA 
                group by s.ColA, s.ColC
                order by 4 desc
            ) s2
group by t.ColA

试试这个 DBFiddle

Answer 2

最简单的方法是根据 ColA 和 ColC 的 COUNT 条记录计算 ROW_NUMBER 或 DENSE_RANK。

如果出现平局，DENSE_RANK = 1 可能显示超过 1 个顶部。

SELECT 
  ColA
, TotalColB AS Total
, ColC AS Lable
FROM
(
  SELECT ColA, ColC
  , TotalColB = SUM(SUM(ColB)) OVER (PARTITION BY ColA)
  , Rnk = DENSE_RANK() OVER (PARTITION BY ColA ORDER BY COUNT(*) DESC)
  FROM YourTable 
  GROUP BY ColA, ColC
) q
WHERE Rnk = 1
ORDER BY ColA;

ColA Total Lable

A 100 aaa

B 60 bbb

在 db<>fiddle here

上测试

SQL 服务器：显示字符串多数

SQL Server: show string majority

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