OracleRowUpdatingEventArgs Класс

Определение

public ref class OracleRowUpdatingEventArgs sealed : System::Data::Common::RowUpdatingEventArgs

public sealed class OracleRowUpdatingEventArgs : System.Data.Common.RowUpdatingEventArgs

type OracleRowUpdatingEventArgs = class
    inherit RowUpdatingEventArgs

Public NotInheritable Class OracleRowUpdatingEventArgs
Inherits RowUpdatingEventArgs

Наследование

Object

EventArgs

RowUpdatingEventArgs

OracleRowUpdatingEventArgs

Примеры

В следующем примере показано, как использовать как события, RowUpdating так и RowUpdated события.

Событие возвращает следующие выходные RowUpdating данные:

Event Arguments: (command=OracleCommand commandType=2 status=0)

Событие возвращает следующие выходные RowUpdated данные:

Event Arguments: (command=OracleCommand commandType=2 recordsAffected=1 row=DataRow[37] status=0)

// handler for RowUpdating event
private static void OnRowUpdating(object sender, OracleRowUpdatingEventArgs e)
{
    PrintEventArgs(e);
}

//Handler for RowUpdated event.
private static void OnRowUpdated(object sender, OracleRowUpdatedEventArgs e)
{
    PrintEventArgs(e);
}

public static int Main(String[] args)
{
    const string CONNECTION_STRING = "Data Source=Oracle8i;Integrated Security=yes";
    const string SELECT_ALL = "SELECT * FROM Scott.Emp";

    //Create DataAdapter.
    OracleDataAdapter rAdapter    = new OracleDataAdapter(SELECT_ALL, CONNECTION_STRING);

    //Create and fill DataSet (Select only first 5 rows.).
    DataSet rDataSet = new DataSet();
    rAdapter.Fill(rDataSet, 0, 5, "Table");

    //Modify DataSet.
    DataTable rTable = rDataSet.Tables["Table"];
    rTable.Rows[0][1] = "DYZY";

    //Add handlers.
    rAdapter.RowUpdating += new OracleRowUpdatingEventHandler( OnRowUpdating );
    rAdapter.RowUpdated += new OracleRowUpdatedEventHandler( OnRowUpdated );

    //Update--this operation fires two events (RowUpdating and RowUpdated) for each changed row.
    rAdapter.Update(rDataSet, "Table");

    //Remove handlers.
    rAdapter.RowUpdating -= new OracleRowUpdatingEventHandler( OnRowUpdating );
    rAdapter.RowUpdated -= new OracleRowUpdatedEventHandler( OnRowUpdated );
    return 0;
}

private static void PrintEventArgs(OracleRowUpdatingEventArgs args)
{
    Console.WriteLine("OnRowUpdating");
    Console.WriteLine("  event args: ("+
        " command=" + args.Command +
        " commandType=" + args.StatementType +
        " status=" + args.Status + ")");
}

private static void PrintEventArgs(OracleRowUpdatedEventArgs args)
{
    Console.WriteLine("OnRowUpdated");
    Console.WriteLine("  event args: ("+
        " command=" + args.Command +
        " commandType=" + args.StatementType +
        " recordsAffected=" + args.RecordsAffected +
        " status=" + args.Status + ")");
}

'Handler for RowUpdating event.
Private Shared Sub OnRowUpdating(sender As Object, e As OracleRowUpdatingEventArgs)
    PrintEventArgs(e)
End Sub

'Handler for RowUpdated event.
Private Shared Sub OnRowUpdated(sender As Object, e As OracleRowUpdatedEventArgs)
    PrintEventArgs(e)
End Sub

'Entry point which delegates to C-style main Private Function.
Public Overloads Shared Sub Main()
    System.Environment.ExitCode = Main(System.Environment.GetCommandLineArgs())
End Sub

Overloads Public Shared Function Main(args() As String) As Integer
    Const CONNECTION_STRING As String = "Data Source=Oracle8i;Integrated Security=yes"
    Const SELECT_ALL As String = "SELECT * FROM Scott.Emp"
    
    'Create DataAdapter.
    Dim rAdapter As New OracleDataAdapter(SELECT_ALL, CONNECTION_STRING)
    
    'Create and fill DataSet (Select only first 5 rows.).
    Dim rDataSet As New DataSet()
    rAdapter.Fill(rDataSet, 0, 5, "Table")
    
    'Modify DataSet.
    Dim rTable As DataTable = rDataSet.Tables("Table")
    rTable.Rows(0)(1) = "DYZY"
    
    'Add handlers.
    AddHandler rAdapter.RowUpdating, AddressOf OnRowUpdating
    AddHandler rAdapter.RowUpdated, AddressOf OnRowUpdated
    
    'Update--this operation fires two events (RowUpdating and RowUpdated) for each changed row. 
    rAdapter.Update(rDataSet, "Table")
    
    'Remove handlers.
    RemoveHandler rAdapter.RowUpdating, AddressOf OnRowUpdating
    RemoveHandler rAdapter.RowUpdated, AddressOf OnRowUpdated
    Return 0
End Function 'Main

Overloads Private Shared Sub PrintEventArgs(args As OracleRowUpdatingEventArgs)
    Console.WriteLine("OnRowUpdating")
    Console.WriteLine("  event args: (" & _
                    " command=" & _
                    args.Command.CommandText & _
                    " commandType=" & _
                    args.StatementType & _
                    " status=" & _
                    args.Status & _
                    ")")
End Sub


Overloads Private Shared Sub PrintEventArgs(args As OracleRowUpdatedEventArgs)
    Console.WriteLine("OnRowUpdated")
    Console.WriteLine("  event args: (" & _
                    " command=" & _
                    args.Command.CommandText & _
                    " commandType=" & _
                    args.StatementType & _
                    " recordsAffected=" & _
                    args.RecordsAffected & _
                    " status=" & _
                    args.Status & _
                    ")")
End Sub

Комментарии

Событие RowUpdating вызывается перед строкой Update .

При использовании Updateдля каждой строки данных обновляется два события. Порядок выполнения выглядит следующим образом:

1. Значения в этом DataRow файле перемещаются в значения параметров.

2. Возникает событие OnRowUpdating.

3. Выполняется команда.

4. Если задано FirstReturnedRecordзначение команды, первый возвращенный результат помещается в .DataRow

5. Если есть выходные параметры, они помещаются в .DataRow

6. Возникает событие OnRowUpdated.

7. AcceptChanges вызывается.