SqlDataAdapter.RowUpdating Event

Definition

在对数据源执行命令前的 Update(DataSet) 过程中发生。Occurs during Update(DataSet) before a command is executed against the data source. 尝试进行更新,因此激发了该事件。The attempt to update is made, so the event fires.

public:
 event System::Data::SqlClient::SqlRowUpdatingEventHandler ^ RowUpdating;
public event System.Data.SqlClient.SqlRowUpdatingEventHandler RowUpdating;
[System.Data.DataSysDescription("DbDataAdapter_RowUpdating")]
public event System.Data.SqlClient.SqlRowUpdatingEventHandler RowUpdating;
member this.RowUpdating : System.Data.SqlClient.SqlRowUpdatingEventHandler 
Public Custom Event RowUpdating As SqlRowUpdatingEventHandler 
Attributes

Examples

下面的示例演示如何同时使用 RowUpdatingRowUpdated 事件。The following example shows how to use both the RowUpdating and RowUpdated events.

RowUpdating 事件返回以下输出:The RowUpdating event returns this output:

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

RowUpdated 事件返回以下输出:The RowUpdated event returns this output:

事件参数:(command = SqlClient commandType = 2 recordsAffected = 1 row = System.object [37] status = 0)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 

Remarks

使用 Update时,每个更新的数据行发生两个事件。When using Update, there are two events that occur per data row updated. 执行顺序如下所示:The order of execution is as follows:

  1. DataRow 中的值将移至参数值。The values in the DataRow are moved to the parameter values.

  2. 引发 OnRowUpdating 事件。The OnRowUpdating event is raised.

  3. 命令执行。The command executes.

  4. 如果命令设置为 FirstReturnedRecord,则返回的第一个结果将放置在 DataRow中。If the command is set to FirstReturnedRecord, the first returned result is placed in the DataRow.

  5. 如果有输出参数,它们会置于 DataRow中。If there are output parameters, they are placed in the DataRow.

  6. 引发 OnRowUpdated 事件。The OnRowUpdated event is raised.

  7. 调用 AcceptChangesAcceptChanges is called.

Applies to

See also