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IDataReader.Read Method

Advances the IDataReader to the next record.

Namespace:  System.Data
Assembly:  System.Data (in System.Data.dll)
'Declaration
Function Read As Boolean

Return Value

Type: System.Boolean
true if there are more rows; otherwise, false.

The default position of the IDataReader is prior to the first record. Therefore you must call Read to begin accessing any data.

While the data reader is in use, the associated connection is busy serving the IDataReader. This is the case until Close is called.

The following example creates instances of three derived classes OleDbConnection, an OleDbCommand, and an OleDbDataReader. The example reads through the data, writing it out to the console. Finally, the example closes the OleDbDataReader, then the OleDbConnection.

Public Sub ReadData(ByVal connectionString As String)
    Dim queryString As String = _
        "SELECT OrderID, CustomerID FROM Orders" 

    Using connection As New OracleConnection(connectionString)
        Dim command As New OracleCommand(queryString, connection)
        connection.Open()

        Dim reader As OracleDataReader
        reader = command.ExecuteReader()

        ' Always call Read before accessing data. 
        While reader.Read()
            Console.WriteLine(reader.GetInt32(0) & ", " & reader.GetString(1))
        End While 

        ' Always call Close when done reading.
        reader.Close()
    End Using 
End Sub

.NET Framework

Supported in: 4.5.1, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.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.

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