Question

我有一个包含以下字段的表格。

Col A  Col B
-----  -----
I1      10
I1      10
I2      16
I3      14
I2      16

我需要一个应该提供输出的查询，如下所示：

ColA   Col B  Count
----   -----  -----
I1      10      2
I2      16      2
I3      14      1

如何为此编写查询。请帮忙

Answer 1

select colA, colB, count(colB) as `Count`
from your_table
group by colA, colB

Answer 2

如果ColB的特定值ColA始终相同，则您可以使用max：

select  ColA
,       max(ColB)
,       count(*)
from    YourTable
group by
        ColA

否则，您必须解释如何计算结果中的ColB值。

Answer 3

SELECT ColA, ColB, Count(ColB) FROM T GROUP BY ColA, ColB

Answer 4

使用GROUP BY

SELECT  colA, colB, COUNT(colB) as Total
   FROM tableName
   GROUP BY colA, colB

Answer 5

请尝试这个并告诉我

select [Col A] ,[Col B] ,count(*) [Count]
    from <table>
    group by [Col A] ,[Col B]
    order by [Col A]

Answer 6

您可以使用此解决方案：

SELECT ColA, ColB, COUNT(1) AS Count
FROM tbl
GROUP BY ColA, ColB

Answer 7

试试这个：

SELECT ColA, colB, COUNT(colB) AS Count
FROM TableName
GROUP BY ColA,ColB 
ORDER BY ColA,ColB