DataTableReader.GetDataTypeName(Int32) Method

Reference

Definition

Namespace:: System.Data

Assemblies:: netstandard.dll, System.Data.Common.dll

Assembly:: System.Data.Common.dll

Assembly:: System.Data.dll

Assembly:: netstandard.dll

Source:: DataTableReader.cs

Source:: DataTableReader.cs

Source:: DataTableReader.cs

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Gets a string representing the data type of the specified column.

public:
 override System::String ^ GetDataTypeName(int ordinal);

public override string GetDataTypeName(int ordinal);

override this.GetDataTypeName : int -> string

Public Overrides Function GetDataTypeName (ordinal As Integer) As String

Parameters

ordinal: Int32

The zero-based column ordinal.

Returns

String

A string representing the column's data type.

Exceptions

ArgumentOutOfRangeException

The index passed was outside the range of 0 to FieldCount - 1.

InvalidOperationException

An attempt was made to read or access a column in a closed DataTableReader.

Examples

The following console application displays a list of fields and their type names from a simple DataTable:

private static void TestGetTypeName()
{
    DataTable table = GetCustomers();
    using (DataTableReader reader = new DataTableReader(table))
    {
        for (int i = 0; i < reader.FieldCount; i++)
        {
            Console.WriteLine("{0}: {1}", reader.GetName(i),
                reader.GetDataTypeName(i));
        }
    }
    Console.WriteLine("Press Enter to finish.");
    Console.ReadLine();
}

private static DataTable GetCustomers()
{
    // Create sample Customers table, in order
    // to demonstrate the behavior of the DataTableReader.
    DataTable table = new DataTable();
    // Create two columns, ID and Name.
    DataColumn idColumn = table.Columns.Add("ID", typeof(int));
    table.Columns.Add("Name", typeof(string ));
    // Set the ID column as the primary key column.
    table.PrimaryKey = new DataColumn[] { idColumn };

    table.Rows.Add(new object[] { 1, "Mary" });
    table.Rows.Add(new object[] { 2, "Andy" });
    table.Rows.Add(new object[] { 3, "Peter" });
    table.Rows.Add(new object[] { 4, "Russ" });
    return table;
}

Private Sub TestGetTypeName()
   Dim table As DataTable = GetCustomers()
   Using reader As New DataTableReader(table)
      For i As Integer = 0 To reader.FieldCount - 1
         Console.WriteLine("{0}: {1}", _
            reader.GetName(i), reader.GetDataTypeName(i))
      Next
   End Using

   Console.WriteLine("Press Enter to finish.")
   Console.ReadLine()
End Sub

Private Function GetCustomers() As DataTable
   ' Create sample Customers table, in order
   ' to demonstrate the behavior of the DataTableReader.
   Dim table As New DataTable

   ' Create two columns, ID and Name.
   Dim idColumn As DataColumn = table.Columns.Add("ID", _
     GetType(Integer))
   table.Columns.Add("Name", GetType(String))

   ' Set the ID column as the primary key column.
   table.PrimaryKey = New DataColumn() {idColumn}

   table.Rows.Add(New Object() {1, "Mary"})
   table.Rows.Add(New Object() {2, "Andy"})
   table.Rows.Add(New Object() {3, "Peter"})
   table.Rows.Add(New Object() {4, "Russ"})
   Return table
End Function

The Console window displays the following results:

ID: Int32  
Name: String

Remarks

The GetDataTypeName method always returns the type of the underlying DataColumn instead of a provider-specific type.

Applies to

Product	Versions
.NET	Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9, 10
.NET Framework	2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard	2.0, 2.1

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