IDataReader.Read Method ()

 

Advances the IDataReader to the next record.

Namespace:   System.Data
Assembly:  System.Data (in System.Data.dll)

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
Available since 1.1
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