var query = from g in dt_stu.AsEnumerable()
group g by new {
t1 = <string>("STU_ID"),
t2 = <string>("CLASS_ID")
} into m
select new
{
STU_ID = .t1,
CLASS_ID=.t2,
成绩总合计 = (a => <decimal>("成绩")),
优秀人数 = (a => <decimal>("成绩")>95)
};
DataTable dt_article = (query);
/// <summary>
/// LINQ返回DataTable类型
/// </summary>
/// <typeparam name="T"> </typeparam>
/// <param name="varlist"> </param>
/// <returns> </returns>
public static DataTable ToDataTable<T>(IEnumerable<T> varlist)
{
DataTable dtReturn = new DataTable();
// column names
PropertyInfo[] oProps = null;
if (varlist == null)
return dtReturn;
foreach (T rec in varlist)
{
if (oProps == null)
{
oProps = ((Type)()).GetProperties();
foreach (PropertyInfo pi in oProps)
{
Type colType = ;
if (() && (()
== typeof(Nullable<>)))
{
colType = ()[0];
}
(new DataColumn(, colType));
}
}
DataRow dr = ();
foreach (PropertyInfo pi in oProps)
{
dr[] = (rec, null) == null ? :
(rec, null);
}
(dr);
}
return dtReturn;
}