NK
и кто бы мог подумать...
SELECT [t0].*
FROM
ProductGroups AS p
LEFT JOIN
(
SELECT *
FROM
(
SELECT *, ROW_NUMBER() OVER(PARTITION BY p0.GroupId ORDER BY p0.Name) AS row
FROM [Products] AS [p0]
) AS [t]
WHERE [t].[row] <= 1
) AS t0 ON p.Id = t0.GroupId
