Subquery returning csv written values in a Main Query Column, possible?

https://stackoverflow.com/questions/7486468

23-01-2021
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Question

I got to tables.

TABLE 1: [..fields..] [CATEGORIE] [..fields..]

TABLE 2: [..fields..] [ID] [CATEGORIE] [..fields..]

I want to connect a bit special and tried it like this:

SELECT [..other fields..], CATEGORIE, (SELECT ID FROM TABLE2 WHERE TABLE2.CATEGORIE = TABLE1.CATEGORIE) FROM TABLE1;

I want to have the IDs of the SubQuery in on Column of the Main Query

like that ( [] are representing columns)

[resultfield1] [resultfield2] [resultfield3] [ID1,ID2,ID3,ID4,...]

is there a way to afford it?

Help is very appreciated,

thanks in advance

Solution

As hard as it is to read understand your question, what you want is to use FOR XML PATH:

select 
    categorie, 
    stuff((select ', ' + id
           from table2 t2 where t1.categorie = t2.categorie
           for xml path('')),
          1,2,'') [IDs]
from table1 t1