Редагувати

Поділитися через


OracleDataReader.Read Method

Definition

Advances the OracleDataReader to the next record.

public:
 virtual bool Read();
public:
 override bool Read();
public bool Read ();
public override bool Read ();
abstract member Read : unit -> bool
override this.Read : unit -> bool
override this.Read : unit -> bool
Public Function Read () As Boolean
Public Overrides Function Read () As Boolean

Returns

true if there are more rows; otherwise, false.

Implements

Examples

The following example creates an OracleConnection, an OracleCommand, and an OracleDataReader. The example reads through the data, writing it out to the console. Finally, the example closes the OracleDataReader, then the OracleConnection.

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

Remarks

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

More than one OracleDataReader can be open at any given time.

Applies to