convert linq query results to datatable C# - asp.net

Question

I want to convert the linq query results to datatable so that I can assign datatable to GridView to show it on asp page.
However I am not able to convert the results to datatable, I am not getting CopyToTable() method in my code.
please advise what am I doing wrong here?
var gradeData = (from data in oAngieCtxt.prc_ShopInstanceCustomersData(Convert.ToInt32(this.ShopInstanceID), 10000, false)
.Where( row => row.RecievedPoints != "n/a" )
.GroupBy(row => new { row.Name })
.Select(g => new GroupedPoints()
{
Name = g.Key.Name,
TotalPoints = g.Sum(x => Convert.ToDouble(x.RecievedPoints) * (x.Weightage.ToString() == "0.00" ? 1 : Convert.ToDouble(x.Weightage)))
})
select data).ToList();
DataTable dt = gradeData --gradeData.CopyToTable()
Note: reference to dataextentions dll is available.
Thanks in advance

Answer 1

You should get DataTableExtensions.CopyToDataTable
Remove ToList().
CopyToDataTable is an IEnumerable<DataRow> extension (unfortunately).
There is a solution with custom CopyToDataTable extension method below.
var gradeData = (from data in oAngieCtxt.prc_ShopInstanceCustomersData(
Convert.ToInt32(this.ShopInstanceID), 10000, false)
.Where( row => row.RecievedPoints != "n/a" )
.GroupBy(row => new { row.Name })
.Select(g => new
{
Name = g.Key.Name,
TotalPoints = g.Sum(x => Convert.ToDouble(x.RecievedPoints)
* (x.Weightage.ToString() == "0.00" ? 1
: Convert.ToDouble(x.Weightage)))
})
select data);
var dt = gradeData.CopyToDataTable();
Edit:
Here is a more useful implementation of CopyToDataTable There is no type constraint to DataRow.
public static class DataSetLinqOperators
{
public static DataTable CopyToDataTable<T>(this IEnumerable<T> source)
{
//you find the ObjectShredder implementation on the blog wich was linked.
return new ObjectShredder<T>().Shred(source, null, null);
}
public static DataTable CopyToDataTable<T>(this IEnumerable<T> source,
DataTable table, LoadOption? options)
{
return new ObjectShredder<T>().Shred(source, table, options);
}
}

Answer 2

First declare a new DataTable and add columns, in this :
DataTable dt = new DataTable();
dt.Columns.Add("FirstName");
dt.Columns.Add("LastName");
DataRow row = null;
Now I simply iterate through the query and fill a DataTable:
foreach (var rowObj in query)
{
row = dt.NewRow();
dt.Rows.Add(rowObj.FirstName, rowObj.LastName);
}

Answer 3

If you want to have you own extension method then you could always do something like this:
public static DataTable ToDataTable<T>(this IQueryable items)
{
Type type = typeof(T);
var props = TypeDescriptor.GetProperties(type)
.Cast<PropertyDescriptor>()
.Where(propertyInfo => propertyInfo.PropertyType.Namespace.Equals("System"))
.Where(propertyInfo => propertyInfo.IsReadOnly == false)
.ToArray();
var table = new DataTable();
foreach (var propertyInfo in props)
{
table.Columns.Add(propertyInfo.Name, Nullable.GetUnderlyingType(propertyInfo.PropertyType) ?? propertyInfo.PropertyType);
}
foreach (var item in items)
{
table.Rows.Add(props.Select(property => property.GetValue(item)).ToArray());
}
return table;
}
You will need to reference both of these
using System.ComponentModel;
using System.Data;