Question

var groups = from p in dc.Pool
             join pm in dc.PoolMembers on p.ID equals pm.PoolID
             group p by p.Group into grp
             select new { grp.ID };

这不起作用。基本上我想进行分组，然后选择某些列，但是当我select new { grp. }时，我没有智能感知，所以我显然做错了。

有什么想法吗？

Answer 1

我不确定但是，以下代码是否有效？

var groups = from p in dc.Pool
             join pm in dc.PoolMembers on p.ID equals pm.PoolID
             group p by p.Group into grp
             select grp.Select(g=> g.ID);

修改

var groups = from p in dc.Pool
             join pm in dc.PoolMembers on p.ID equals pm.PoolID
             group p by p.Group into grp
             select grp.Select(g=> new{ 
                  Id = g.Id, 
                  GroupName = grp.Key.Name,
                  Contribution = pm.Contribution,
                  GameName = p.GameName, });

Answer 2

我认为这就是你要找的东西

      var groups = from p in dc.Pool
               join pm in dc.PoolMembers on p.ID equals pm.PoolID
               group p by p.Group into grp
               select new { grp.Key.ID, GroupName = grp.Key.Group.Name, grp.Key.GameName };

Answer 3

var pools = 
  from p in dc.Pool
  select new
  {
    p.ID,
    GroupName = p.Group.Name,
    Contribution = p.PoolMembers.Sum(pm => pm.Contribution),
    p.GameName
  };

Linq 2 SQL分组问题

3 个答案: