AsEnumerable Method
Collapse the table of content
Expand the table of content

DataTableExtensions.AsEnumerable Method (DataTable)


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


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.

Exception Condition

The source DataTable is null.

Language-Integrated Query (LINQ) queries work on data sources that implement the IEnumerable<T> interface or the T:System.Query.IQueryable`1 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) {

   static void Main(string[] args) {
      DataTable table = new DataTable();

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

      Program inst = new Program();

.NET Framework
Available since 3.5
Return to top
© 2015 Microsoft