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
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.