вещи в SQL Server
DECLARE @Table1 TABLE(ID INT, Value INT)
INSERT INTO @Table1 VALUES (1,100),(1,200),(1,300),(1,400)
SELECT ID
,STUFF((SELECT ', ' + CAST(Value AS VARCHAR(10)) [text()]
FROM @Table1
WHERE ID = t.ID
FOR XML PATH(''), TYPE)
.value('.','NVARCHAR(MAX)'),1,1,' ') List_Output
FROM @Table1 t
GROUP BY ID
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