如果另一列具有多个值，如何选择按列分组的值

I am trying to get from a table those values in column1, that have some values in column2.

我试图从表中获取column1中的值，这些值在column2中有一些值。

For example, I want to get A because it has "1,2,3". (Expected Output of select: A)

例如，我想获得A，因为它有“1,2,3”。（预期产出的选择：A）

---
A|1
A|2
A|3
A|4
B|1
B|3
---

This is what I've tried

这就是我尝试过的

SELECT * FROM sample_table WHERE Col2 in (1,2,3) GROUP BY col1

I understand perfectly it won't work, since I am just putting the condition that column 2 must have one of those values, and then I group them by Col1, so It will take (A,1),(A,2),(A,3),(B,1),(B,2) -> group them by Col1 and give me (A) and (B)

我完全理解它不会起作用，因为我只是把第2列必须具有其中一个值的条件，然后我将它们按Col1分组，所以它需要（A，1），（A，2），（A，3），（B，1），（B，2） - >按Col1分组给我（A）和（B）

I really have no clue how I could force it to have ALL the 3 values

我真的不知道如何强制它拥有所有3个值

Here is the fiddle to try it

这是尝试它的小提琴

NOTE

注意

Please feel free to edit the post in order to make it more understandable, I have tried my best, but I know its not very well explained, specially the title

请随时编辑帖子，以使其更容易理解，我已尽力了，但我知道它不是很好解释，特别是标题

Thank you very much

非常感谢你

2 个解决方案

#1

You can use the HAVING() clause :

您可以使用HAVING（）子句：

SELECT col1
WHERE Col2 in (1,2,3) 
GROUP BY col1
HAVING COUNT(col2) = 3

This will show only results that have 3 values , and since you filtered only for 1,2,3 , if there are 3, it those 3.

这将仅显示具有3个值的结果，并且由于您仅针对1,2,3进行过滤，如果有3个，则为3。

Note : If the values on col2 are not distinct , E.G. it's possible for this data to appear:

注意：如果col2上的值不明显，则E.G.这些数据可能会出现：

A | 1
A | 1
A | 2

Then add DISTINCT inside the parentheses of the count.

然后在计数的括号内添加DISTINCT。

#2

You could try to play with HAVING and GROUP_CONCAT:

您可以尝试使用HAVING和GROUP_CONCAT：

SELECT COL1 
FROM sample
GROUP BY COL1
HAVING GROUP_CONCAT(DISTINCT COL2 ORDER BY COL2 ASC) LIKE '%1,2,3%'

#1