Export (0) Print
Expand All
3 out of 4 rated this helpful - Rate this topic

DataTableExtensions.AsEnumerable Method

Returns an IEnumerable<T> object, where the generic parameter T is DataRow. This object can be used in a LINQ expression or method query.

Namespace:  System.Data
Assembly:  System.Data.DataSetExtensions (in System.Data.DataSetExtensions.dll)
public static EnumerableRowCollection<DataRow> AsEnumerable(
	this DataTable source
)

Parameters

source
Type: System.Data.DataTable

The source DataTable to make enumerable.

Return Value

Type: System.Data.EnumerableRowCollection<DataRow>
An IEnumerable<T> object, where the generic parameter T is DataRow.

Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type DataTable. When you use instance method syntax to call this method, omit the first parameter. For more information, see Extension Methods (Visual Basic) or Extension Methods (C# Programming Guide).
ExceptionCondition
ArgumentNullException

The source DataTable is null.

Language-Integrated Query (LINQ) queries work on data sources that implement the IEnumerable<T> interface or the IQueryable interface. The DataTable class does not implement either interface, so you must call the AsEnumerable method to use the DataTable as a source in the From clause of a LINQ query. You can also obtain custom, domain-specific operators, such as CopyToDataTable, by returning an IEnumerable<T> object. 

The enumerable object returned by the AsEnumerable method is permanently bound to the DataTable that produced it. Multiple calls to the AsEnumerable method will return multiple, independent queryable objects that are all bound to the source DataTable.

In the following sample, the DisplayProducts method receives a DataTable that contains a DataColumn named ProductName, extracts the ProductName values and then prints the values.

using System;
using System.Data;

class Program {
   public void DisplayProducts(DataTable table) {
      var productNames = from products in table.AsEnumerable() select products.Field<string>("ProductName");
      Console.WriteLine("Product Names: ");
      foreach (string productName in productNames) {
         Console.WriteLine(productName);
      }
   }

   static void Main(string[] args) {
      DataTable table = new DataTable();
      table.Columns.Add("ID");
      table.Columns.Add("ProductName");

      table.Rows.Add("1", "Chai");
      table.Rows.Add("2", "Queso Cabrales");
      table.Rows.Add("3", "Tofu");

      Program inst = new Program();
      inst.DisplayProducts(table);
   }
}

.NET Framework

Supported in: 4.5.1, 4.5, 4, 3.5

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Did you find this helpful?
(1500 characters remaining)
Thank you for your feedback
Show:
© 2014 Microsoft. All rights reserved.