Szerkesztés

Megosztás a következőn keresztül:

OdbcDataReader.Read Method

  • Reference

Definition

Namespace:
System.Data.Odbc
Assembly:
System.Data.Odbc.dll
Assembly:
System.Data.dll
Package:
System.Data.Odbc v8.0.1
Package:
System.Data.Odbc v9.0.0-rc.2.24473.5
Source:
OdbcDataReader.cs
Source:
OdbcDataReader.cs
Source:
OdbcDataReader.cs
Source:
OdbcDataReader.cs
Source:
OdbcDataReader.cs

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

Returns

Boolean

true if there are more rows; otherwise false.

Implements

Read()

Examples

The following example creates an OdbcConnection, an OdbcCommand, and an OdbcDataReader. The example reads through the data, writing it out to the console. 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

Remarks

The default position of the OdbcDataReader is before the first record. Therefore, you must call Read to start accessing any data.

While the OdbcDataReader is being used, the associated OdbcConnection is busy serving it until you call Close.

Applies to

See also