Lingua

SqlDataAdapter.RowUpdated Event

Definizione

Spazio dei nomi:
System.Data.SqlClient
Assembly:
System.Data.dll
Origine:
System.Data.SqlClient.notsupported.cs

Si verifica durante Update(DataSet) l'esecuzione di un comando sull'origine dati. Viene eseguito il tentativo di aggiornamento, quindi viene generato l'evento.

Per il nuovo sviluppo, usare Microsoft. Data.SqlClient. Questa pagina documenta System.Data.SqlClient.

public:
 event System::Data::SqlClient::SqlRowUpdatedEventHandler ^ RowUpdated;
[System.Data.DataSysDescription("DbDataAdapter_RowUpdated")]
public event System.Data.SqlClient.SqlRowUpdatedEventHandler RowUpdated;
public event System.Data.SqlClient.SqlRowUpdatedEventHandler RowUpdated;
[<System.Data.DataSysDescription("DbDataAdapter_RowUpdated")>]
member this.RowUpdated : System.Data.SqlClient.SqlRowUpdatedEventHandler 
member this.RowUpdated : System.Data.SqlClient.SqlRowUpdatedEventHandler 
Public Custom Event RowUpdated As SqlRowUpdatedEventHandler

Tipo evento

SqlRowUpdatedEventHandler
Attributi
DataSysDescriptionAttribute

Esempio

Nell'esempio seguente viene illustrato come usare gli RowUpdating eventi e RowUpdated .

L'evento RowUpdating restituisce questo output:

argomenti evento: (command=System.Data.SqlClient.SqlCommand commandType=2 status=0)

L'evento RowUpdated restituisce questo output:

argomenti evento: (command=System.Data.SqlClient.SqlCommand commandType=2 recordsAffected=1 row=System.Data.DataRow[37] status=0)

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

// handler for RowUpdated event
private static void OnRowUpdated(object sender, SqlRowUpdatedEventArgs e)
{
    PrintEventArgs(e);
}

public static int Main()
{
    const string connectionString = "...";
    const string queryString = "SELECT * FROM Products";

    // create DataAdapter
    SqlDataAdapter adapter = new(queryString, connectionString);
    SqlCommandBuilder builder = new(adapter);

    // Create and fill DataSet (select only first 5 rows)
    DataSet dataSet = new();
    adapter.Fill(dataSet, 0, 5, "Table");

    // Modify DataSet
    DataTable table = dataSet.Tables["Table"];
    table.Rows[0][1] = "new product";

    // add handlers
    adapter.RowUpdating += new SqlRowUpdatingEventHandler(OnRowUpdating);
    adapter.RowUpdated += new SqlRowUpdatedEventHandler(OnRowUpdated);

    // update, this operation fires two events
    // (RowUpdating/RowUpdated) per changed row
    adapter.Update(dataSet, "Table");

    // remove handlers
    adapter.RowUpdating -= new SqlRowUpdatingEventHandler(OnRowUpdating);
    adapter.RowUpdated -= new SqlRowUpdatedEventHandler(OnRowUpdated);
    return 0;
}

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

private static void PrintEventArgs(SqlRowUpdatedEventArgs 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 SqlRowUpdatingEventArgs)
        PrintEventArgs(e)
    End Sub

    ' handler for RowUpdated event
    Private Shared Sub OnRowUpdated(sender As Object, e As SqlRowUpdatedEventArgs)
        PrintEventArgs(e)
    End Sub

    Public Overloads Shared Function Main(args() As String) As Integer
        Const connectionString As String = "..."
        Const queryString As String = "SELECT * FROM Products"

        ' create DataAdapter
        Dim adapter As New SqlDataAdapter(queryString, connectionString)
        Dim builder As New SqlCommandBuilder(adapter)

        ' Create and fill DataSet (select only first 5 rows)
        Dim dataSet As New DataSet()
        adapter.Fill(dataSet, 0, 5, "Table")

        ' Modify DataSet
        Dim table As DataTable = dataSet.Tables("Table")
        table.Rows(0)(1) = "new product"

        ' add handlers
        AddHandler adapter.RowUpdating, AddressOf OnRowUpdating
        AddHandler adapter.RowUpdated, AddressOf OnRowUpdated

        ' update, this operation fires two events
        '(RowUpdating/RowUpdated) per changed row
        adapter.Update(dataSet, "Table")

        ' remove handlers
        RemoveHandler adapter.RowUpdating, AddressOf OnRowUpdating
        RemoveHandler adapter.RowUpdated, AddressOf OnRowUpdated
        Return 0
    End Function


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


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

Commenti

Quando si usa Update, sono presenti due eventi che si verificano per ogni riga di dati aggiornata. L'ordine di esecuzione è il seguente:

  1. I valori in DataRow vengono spostati nei valori dei parametri.

  2. Viene generato l'evento OnRowUpdating.

  3. Il comando viene eseguito.

  4. Se il comando è impostato su FirstReturnedRecord, il primo risultato restituito viene inserito in DataRow.

  5. Se sono presenti parametri di output, vengono inseriti in DataRow.

  6. Viene generato l'evento OnRowUpdated.

  7. Si chiama AcceptChanges.

Si applica a

Vedi anche