Help me select Join in linq

var lst1 = from a in tbl1
           select new {Date=a.Date,User=a.User};
var result =  from b in tbl1
              join u in lst1 on b.User equals u.User
              Select b;

var result = from b in tbl1
             join (from a in tbl1
                   select new {Date=a.Date,User=a.User};)u
             on b.User equals u.User
             Select b;