linq group 有关问题

linq group 问题
IDName GroupName
14x6 box 4x6
25x7 bag 5x7
34x6 container 4x6
45x7 box 5x7
54x6 bag 4x6
65x7 container 5x7
75x6 bottle 5x6
812x12 box 12x12
95x6 box 5x6
1016x20 container 16x20

如何根据groupName把相关的ID放到一起，
结果得到一个2列的数据，

4x6 1,3,5
5x7 2,4,6
5x6 7,9
12x12 8
16x20 10





[解决办法]
var query = from x in data
group x by x.groupName into g
select new { groupname = g.Key, items = string.Join(",", g.Select(x => x.ID).ToArray()) };
[解决办法]
var query = from x in data
group x by x.groupName into g
select g.Key + string.Join("", g.Select(x => string.Format("<product productID='{0}' productName='{1}' />", x.ID, x.Name)).ToArray());