OleDbDataReader.Read Método

public:
 override bool Read();

public:
 virtual bool Read();

public override bool Read ();

public bool Read ();

override this.Read : unit -> bool

abstract member Read : unit -> bool
override this.Read : unit -> bool

Public Overrides Function Read () As Boolean

Public Function Read () As Boolean

Retornos

true se houver mais linhas; caso contrário, false.

Implementações

Exemplos

O exemplo a seguir cria um OleDbConnection, um OleDbCommande um OleDbDataReader. O exemplo lê os dados, gravando-os no console. Por fim, o exemplo fecha o OleDbDataReader e, em seguida, o OleDbConnection.

private static void ReadData(string connectionString)
{
    string queryString = "SELECT OrderID, CustomerID FROM Orders";
    using (OracleConnection connection = new OracleConnection(connectionString))
    {
        OracleCommand command = new OracleCommand(queryString, connection);
        connection.Open();
        OracleDataReader reader;
        reader = command.ExecuteReader();

        // Always call Read before accessing data.
        while (reader.Read())
        {
            Console.WriteLine(reader.GetInt32(0) + ", " + reader.GetString(1));
        }

        // Always call Close when done reading.
        reader.Close();
    }
}

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

Comentários

A posição padrão do OleDbDataReader é antes do primeiro registro. Portanto, você deve chamar Read para começar a acessar quaisquer dados.

Enquanto o OleDbDataReader estiver sendo usado, o associado OleDbConnection estará ocupado servindo-o até que você chame Close.

Aplica-se a

Confira também

• DataAdapters e DataReaders