OdbcDataReader.Read Método

Definição

Avança o OdbcDataReader para o próximo registro.Advances the OdbcDataReader to the next record.

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

Boolean

true se houver mais linhas; caso contrário, false.true if there are more rows; otherwise false.

Implementações

Exemplos

O exemplo a seguir cria um OdbcConnection , um OdbcCommand e um OdbcDataReader .The following example creates an OdbcConnection, an OdbcCommand, and an OdbcDataReader. O exemplo lê os dados, gravando-os no console.The example reads through the data, writing it out to the console. Por fim, o exemplo fecha o OdbcDataReader e, em seguida, o OdbcConnection .Finally, the example closes the OdbcDataReader, and then the OdbcConnection.

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 de OdbcDataReader é antes do primeiro registro.The default position of the OdbcDataReader is before the first record. Portanto, você deve chamar Read para iniciar o acesso a qualquer dado.Therefore, you must call Read to start accessing any data.

Enquanto o OdbcDataReader estiver sendo usado, o associado OdbcConnection estará ocupado servindo até que você chame Close .While the OdbcDataReader is being used, the associated OdbcConnection is busy serving it until you call Close.

Aplica-se a