linq分组拼接字符串

linq分组拼接字符串

Q:

id  name
1    A
2    A
3    b

 

期望结果

{"1,2","A"}

{"3","b"}

A:

var tbl2 = from item in db.tbl select new {id=item.id.ToString(),item.name };var result = from item in tbl2    group item by item.name into g    select g.Aggregate(        (workingSentence, next) =>            new { ids =workingSentence.id + "," +next.id  , name = g.Key });

B:

var result = from item in tbl    group item by item.name into g    let ids = g.Select(b => b.id.ToString()).ToArray()    select new { id = String.Join(",", ids), name = g.Key };