SqlCeDataAdapter.UpdateCommand 属性

命名空间: System.Data.SqlServerCe
程序集: System.Data.SqlServerCe（在 system.data.sqlserverce.dll 中）

语法

声明
Public Property UpdateCommand As SqlCeCommand
用法
Dim instance As SqlCeDataAdapter
Dim value As SqlCeCommand

value = instance.UpdateCommand

instance.UpdateCommand = value

public SqlCeCommand UpdateCommand { get; set; }

public:
property SqlCeCommand^ UpdateCommand {
    SqlCeCommand^ get ();
    void set (SqlCeCommand^ value);
}

/** @property */
public SqlCeCommand get_UpdateCommand ()

/** @property */
public void set_UpdateCommand (SqlCeCommand value)

public function get UpdateCommand () : SqlCeCommand

public function set UpdateCommand (value : SqlCeCommand)

不适用。

属性值

在 Update 过程中使用的 SqlCeCommand，用于更新数据源中与 DataSet 中已修改的行相对应的记录。

备注

在 Update 期间，如果未设置此属性而且 DataSet 中存在主键信息，则可自动生成 UpdateCommand。若要自动生成此属性，请设置 SelectCommand 属性并使用 SqlCeCommandBuilder。然后，SqlCeCommandBuilder 将生成其他任何未设置的命令。此生成逻辑要求 DataSet 中存在键列信息。

在将 UpdateCommand 分配给以前创建的 SqlCeCommand 时，不克隆 SqlCeCommand。UpdateCommand 维护对以前创建的 SqlCeCommand 对象的引用。

备注

如果执行此命令后返回行，这些行可能会与 DataSet 合并，具体取决于如何设置 SqlCeCommand 对象的 UpdatedRowSource 属性。

示例

下面的示例创建了一个 SqlCeDataAdapter，修改了一个数据集，然后调用了 Update 方法以更新数据源。

Dim cmd As SqlCeCommand = Nothing
Dim adp As SqlCeDataAdapter = Nothing

Try
    adp = New SqlCeDataAdapter()
    Dim conn As New SqlCeConnection("Data Source = MyDatabase.sdf")

    ' Create the SelectCommand
    '
    cmd = conn.CreateCommand()
    cmd.CommandText = "SELECT [Employee ID], [First Name], [Last Name] FROM Employees"
    adp.SelectCommand = cmd

    ' Create the InsertCommand
    '
    cmd = conn.CreateCommand()
    cmd.CommandText = "INSERT INTO Employees ([First Name],[Last Name]) VALUES (@first, @last)"

    Dim p As SqlCeParameter = Nothing

    p = cmd.Parameters.Add("@first", SqlDbType.NVarChar, 10, "First Name")
    p.SourceVersion = DataRowVersion.Original

    p = cmd.Parameters.Add("@last", SqlDbType.NVarChar, 20, "Last Name")
    p.SourceVersion = DataRowVersion.Original

    adp.InsertCommand = cmd

    ' Create the UpdateCommand
    '
    cmd = conn.CreateCommand()
    cmd.CommandText = "UPDATE Employees SET [First Name] = @first, " + _
        "[Last Name] = @last WHERE [Employee ID] = @employeeID"

    p = cmd.Parameters.Add("@first", SqlDbType.NVarChar, 10, "First Name")
    p.SourceVersion = DataRowVersion.Current

    p = cmd.Parameters.Add("@last", SqlDbType.NVarChar, 20, "Last Name")
    p.SourceVersion = DataRowVersion.Current

    p = cmd.Parameters.Add("@employeeID", SqlDbType.NVarChar, 20, "Employee ID")
    p.SourceVersion = DataRowVersion.Original

    adp.UpdateCommand = cmd

    ' Populate the dataset with the results from the SELECT statement
    '
    Dim ds As New DataSet()
    adp.Fill(ds)

    ' Modify the dataset
    '
    MessageBox.Show("Number of rows: " & ds.Tables(0).Rows.Count)

    ' Insert some rows
    '
    ds.Tables(0).Rows.Add(New Object() {Nothing, "Nancy", "Smith"})
    ds.Tables(0).Rows.Add(New Object() {Nothing, "Joe", "Clayton"})

    ' Update some rows
    '
    ds.Tables(0).Rows(1)(1) = "David"
    ds.Tables(0).Rows(1)(2) = "Johnson"

    ' This will execute two INSERT and one UPDATE statements
    '
    adp.Update(ds.Tables(0))
Catch e As Exception
    MessageBox.Show(e.Message)
Finally
    If Not Nothing Is adp.SelectCommand Then
        adp.SelectCommand.Dispose()
    End If
    If Not Nothing Is adp.InsertCommand Then
        adp.InsertCommand.Dispose()
    End If
End Try

SqlCeCommand cmd = null;
SqlCeDataAdapter adp = null;

try
{
    adp = new SqlCeDataAdapter();
    SqlCeConnection conn = new SqlCeConnection("Data Source = MyDatabase.sdf");

    // Create the SelectCommand
    //
    cmd = conn.CreateCommand();
    cmd.CommandText = "SELECT [Employee ID], [First Name], [Last Name] FROM Employees";
    adp.SelectCommand = cmd;

    // Create the InsertCommand
    //
    cmd = conn.CreateCommand();
    cmd.CommandText = "INSERT INTO Employees ([First Name],[Last Name]) VALUES (@first, @last)";

    SqlCeParameter p = null;

    p = cmd.Parameters.Add("@first", SqlDbType.NVarChar, 10, "First Name");
    p.SourceVersion = DataRowVersion.Original;

    p = cmd.Parameters.Add("@last", SqlDbType.NVarChar, 20, "Last Name");
    p.SourceVersion = DataRowVersion.Original;

    adp.InsertCommand = cmd;

    // Create the UpdateCommand
    //
    cmd = conn.CreateCommand();
    cmd.CommandText = "UPDATE Employees SET [First Name] = @first, " +
        "[Last Name] = @last WHERE [Employee ID] = @employeeID";

    p = cmd.Parameters.Add("@first", SqlDbType.NVarChar, 10, "First Name");
    p.SourceVersion = DataRowVersion.Current;

    p = cmd.Parameters.Add("@last", SqlDbType.NVarChar, 20, "Last Name");
    p.SourceVersion = DataRowVersion.Current;

    p = cmd.Parameters.Add("@employeeID", SqlDbType.NVarChar, 20, "Employee ID");
    p.SourceVersion = DataRowVersion.Original;

    adp.UpdateCommand = cmd;

    // Populate the dataset with the results from the SELECT statement
    //
    DataSet ds = new DataSet();
    adp.Fill(ds);

    // Modify the dataset
    //
    MessageBox.Show("Number of rows: " + ds.Tables[0].Rows.Count);

    // Insert some rows
    //
    ds.Tables[0].Rows.Add(new object[] { null, "Nancy", "Smith" });
    ds.Tables[0].Rows.Add(new object[] { null, "Joe", "Clayton" });

    // Update some rows
    //
    ds.Tables[0].Rows[1][1] = "David";
    ds.Tables[0].Rows[1][2] = "Johnson";

    // This will execute two INSERT and one UPDATE statements 
    //
    adp.Update(ds.Tables[0]);

    
}
catch (Exception e)
{
    MessageBox.Show(e.Message);
}
finally
{
    if (null != adp.SelectCommand) adp.SelectCommand.Dispose();
    if (null != adp.InsertCommand) adp.InsertCommand.Dispose();
}

平台

Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

Windows Vista、Microsoft Windows XP SP2 和 Windows Server 2003 SP1 支持 Microsoft .NET Framework 3.0。

版本信息

.NET Framework

受以下版本支持：3.0

.NET Compact Framework

受以下版本支持：2.0、1.0

请参见

参考

SqlCeDataAdapter 类
SqlCeDataAdapter 成员
System.Data.SqlServerCe 命名空间
DeleteCommand
InsertCommand
SelectCommand