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我如何合并和计数除ID列外相同的MySQL行?_Mysql_Count - Fatal编程技术网

我如何合并和计数除ID列外相同的MySQL行?

我如何合并和计数除ID列外相同的MySQL行?,mysql,count,Mysql,Count,我希望能够合并行,并找出除了ID之外有多少行是相同的。例如,如果我要使用此表: +---------+-----------+-----------+ | ID | Col 1 | Col 2 | +---------+-----------+ ----------+ | 1 | 1 | 5 | | 2 | 1 | 5 | | 3 | 4 | 9

我希望能够合并行,并找出除了ID之外有多少行是相同的。例如,如果我要使用此表:

+---------+-----------+-----------+
|  ID     |  Col 1    |  Col 2    |
+---------+-----------+ ----------+
|  1      |  1        |  5        |
|  2      |  1        |  5        |
|  3      |  4        |  9        |
|  4      |  3        |  9        |
|  5      |  1        |  5        |
|  6      |  1        |  5        |
|  7      |  1        |  5        |
|  8      |  4        |  9        |
+---------+-----------+-----------+
它将成为:

+---------+-----------+-----------+---------+
|  ID     |  Col 1    |  Col 2    |  Count  |
+---------+-----------+ ----------+---------+
|  1      |  1        |  5        | 5       |
|  2      |  4        |  9        | 2       |
|  3      |  3        |  9        | 1       |
+---------+-----------+-----------+---------+

对此的查询是什么?

在结果的ID列旁边,我认为您需要:

SELECT Col1, Col2, Count(Col1)
FROM myTable
GROUP BY Col1, Col2

你怎么认为?你试了什么?你在哪里失败了?我认为你的分组方式是错误的,因为ID是唯一的-它应该是按col1,col2分组的
select col1,col2,count(*) as `count`
from table
group by col1,col2