linq to xml中group by的应用

<?xml version="1.0" encoding="utf-8"?>
<users>
    <user>
    <id>003</id>
    <name>小张</name>
    <sex>female</sex>
    <age>30</age>
    <university>南大</university>
    <phone>13328981152</phone>
  </user>
  <user>
    <id>004</id>
    <name>徐越</name>
    <sex>female</sex>
    <age>22</age>
    <university>一个大学</university>
    <phone>13328981152</phone>
  </user>
  <user>
    <id>005</id>
    <name>小樱</name>
    <sex>female</sex>
    <age>22</age>
    <university>南大</university>
    <phone>13328981152</phone>
  </user>
  <user>
    <id>006</id>
    <name>小赵</name>
    <sex>female</sex>
    <age>22</age>
    <university>南邮</university>
    <phone>13328981152</phone>
  </user>
  <user>
    <id>007</id>
    <name>小虎</name>
    <sex>female</sex>
    <age>22</age>
    <university>东南</university>
    <phone>13328981152</phone>
  </user>

 

 /// <summary>
        /// 按学校分组
        /// </summary>
        /// <returns></returns>
        public DataTable GroupBySchool()
        {
            List<ChartCount> listcount = new List<ChartCount>();
            doc = XDocument.Load(path);
            // 计数
            var users = (from u in doc.Element("users").Elements("user")
                       group u by u.Element("university").Value into g
                       select new
                       {
                           g.Key,
                           Num=g.Count()
                       });
            foreach (var user in users)
            {
                ChartCount cc = new ChartCount();
                cc.School = user.Num;
                cc.Count = user.Key;
                listcount.Add(cc);
            }
            return CollectionHelper.ToDataTable(listcount, null);
        }
 
那么我在分组的时候想要获得一些基本信息怎么办呢？
 
        /// <summary>
        /// 按学校分组
        /// </summary>
        /// <returns></returns>
        public DataTable GroupBySchool()
        {
            List<ChartCount> listcount = new List<ChartCount>();
            doc = XDocument.Load(path);
            // 计数
            var users = (from u in doc.Element("users").Elements("user")
                       group u by u.Element("university").Value into g
                       select new
                       {
                             Id=g.Select(u=>u.Element("id").Value),
                             Name=g.Select(u=>u.Element("name").Value),
                             Sex=g.Select(u=>u.Element("sex").Value),
                             Age=g.Select(u=>u.Element("age").Value),
                             School=g.Select(u=>u.Element("university").Value),
                             Phone=g.Select(u=>u.Element("phone").Value) 
                     });
            foreach (var user in users)
            {
                ChartCount cc = new ChartCount();
                cc.School = user.Num;
                cc.Count = user.Key;
                listcount.Add(cc);
            }
            return CollectionHelper.ToDataTable(listcount, null);
        }