OracleDataReader.Read 方法

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

返回

true 如果有更多行，则为否则，为 false.

实现

示例

以下示例创建一个 OracleConnection、一个 OracleCommand和一个 OracleDataReader。 该示例读取数据，并将其写出到控制台。 最后，该示例关闭 OracleDataReader，然后关闭 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

注解

默认位置 OracleDataReader 位于第一条记录之前。 因此，必须调用 Read 以开始访问任何数据。

可以在任意给定时间打开多个 OracleDataReader 。