System.Data Namespace

Represents a collection of columns for a DataTable.

The DataColumnCollection defines the schema of a DataTable, and determines what kind of data each DataColumn can contain. This collection is accessed via the DataTable.Columns property.

Like most data collections in ADO.NET, the DataColumnCollection uses standard collection methods to manage the items in the collection. These include the methods Add, Clear, and Remove.

The collection also includes a Count property to determine how many DataColumn objects are in the collection, and a Contains method to verify whether a specified column index or name exists in the collection.

The following examples demonstrate using the Columns property to print the values of each column in each row of a table.

Private void ColumnsDemo ( DataTable myTable ) {

   foreach ( DataRow myRow in myTable.Rows ) {
      foreach ( DataColumn myCol in myTable.Columns ) {
         Response.Write ( myRow [ myCol ] );
      }
    }
}

Private Sub ColumnsDemo ( ByVal myTable As DataTable )
   Dim myRow As DataRow, myColumn As DataColumn
   For Each myRow in myTable.Rows
      For Each myColumn In myTable.Columns
         Response.Write ( myRow ( myColumn ) )
      Next
   Next
End Sub

Retrieving OleDb Data into a DataSet Run Sample | View Source

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Columns   DataColumn   DataTable   DataRelation   DataRow   DataSet