SqlDataAdapter.RowUpdating Olay

Tanım

Ad Alanı:

System.Data.SqlClient

Bütünleştirilmiş Kod:

System.Data.dll

Veri kaynağında bir komut yürütülmeden önce gerçekleşir Update(DataSet) . Güncelleştirme girişimi yapıldığından olay tetikler.

public:
 event System::Data::SqlClient::SqlRowUpdatingEventHandler ^ RowUpdating;

public event System.Data.SqlClient.SqlRowUpdatingEventHandler RowUpdating;

member this.RowUpdating : System.Data.SqlClient.SqlRowUpdatingEventHandler 

Public Custom Event RowUpdating As SqlRowUpdatingEventHandler 

Olay Türü

SqlRowUpdatingEventHandler

Örnekler

Aşağıdaki örnekte hem hem RowUpdated de olaylarının RowUpdating nasıl kullanılacağı gösterilmektedir.

olay RowUpdating şu çıkışı döndürür:

event args: (command=System.Data.SqlClient.SqlCommand commandType=2 status=0)

olay RowUpdated şu çıkışı döndürür:

event args: (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 =
              "Integrated Security=SSPI;database=Northwind;server=MSSQL1";
    const string queryString = "SELECT * FROM Products";

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

    // Create and fill DataSet (select only first 5 rows)
    DataSet dataSet = new DataSet();
    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 
    
    '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 connectionString As String = _
            "Integrated Security=SSPI;database=Northwind;server=MSSQL1"
        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 
    
    
    Overloads Private 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 
    
    
    Overloads Private 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

Açıklamalar

kullanırken Update, güncelleştirilen veri satırı başına gerçekleşen iki olay vardır. Yürütme sırası aşağıdaki gibidir:

1. içindeki DataRow değerler parametre değerlerine taşınır.

2. Olay OnRowUpdating oluşturulur.

3. Komut yürütülür.

4. Komut olarak FirstReturnedRecordayarlanırsa, döndürülen ilk sonuç içine DataRowyerleştirilir.

5. Çıkış parametreleri varsa, içine yerleştirilirler DataRow.

6. Olay OnRowUpdated oluşturulur.

7. AcceptChanges çağrıldığında.

Ayrıca bkz.

• Verileri Düzenleme (ADO.NET)
• SQL Server için .NET Framework Veri Sağlayıcısı'nı kullanma
• ADO.NET’e Genel Bakış