IDataAdapter.Update(DataSet) 方法


从名为“Table”的 DataSet 为指定的 DataTable 中每个已插入、已更新或已删除的行调用相应的 INSERT、UPDATE 或 DELETE 语句。Calls the respective INSERT, UPDATE, or DELETE statements for each inserted, updated, or deleted row in the specified DataSet from a DataTable named "Table".

 int Update(System::Data::DataSet ^ dataSet);
public int Update (System.Data.DataSet dataSet);
abstract member Update : System.Data.DataSet -> int



用于更新数据源的 DataSetThe DataSet used to update the data source.


DataSet 中成功更新的行数。The number of rows successfully updated from the DataSet.


尝试执行 INSERT、UPDATE 或 DELETE 语句,但没有记录受到影响。An attempt to execute an INSERT, UPDATE, or DELETE statement resulted in zero records affected.


下面的示例使用派生类 OleDbDataAdapterUpdate 数据源。The following example uses the derived class, OleDbDataAdapter, to Update the data source. 此示例假设已创建 OleDbDataAdapterDataSetThis example assumes that you have created an OleDbDataAdapter and a DataSet.

static private DataSet CreateCommandAndUpdate(
    string connectionString,
    string queryString)
    DataSet dataSet = new DataSet();

    using (OleDbConnection connection =
               new OleDbConnection(connectionString))
        OleDbDataAdapter adapter =
            new OleDbDataAdapter();
        adapter.SelectCommand =
            new OleDbCommand(queryString, connection);
        OleDbCommandBuilder builder =
            new OleDbCommandBuilder(adapter);


        // Code to modify data in the DataSet here.

        // Without the OleDbCommandBuilder, this line would fail.
        adapter.UpdateCommand = builder.GetUpdateCommand();
    return dataSet;
Public Function CreateCommandAndUpdate( _
    ByVal connectionString As String, _
    ByVal queryString As String) As DataSet

    Dim dataSet As New DataSet()

    Using connection As New OleDbConnection(connectionString)
        Dim adapter As New OleDbDataAdapter()

        adapter.SelectCommand = New OleDbCommand( _
            queryString, connection)

        Dim builder As OleDbCommandBuilder = _
            New OleDbCommandBuilder(adapter)


        ' Code to modify the data in the DataSet here. 

        ' Without the OleDbCommandBuilder this line would fail.
    End Using
    Return dataSet
End Function


当应用程序调用 Update 方法时,IDataAdapter 将检查 RowState 属性,并根据在 DataSet中配置的索引的顺序对每个行执行所需的 INSERT、UPDATE 或 DELETE 语句。When an application calls the Update method, the IDataAdapter examines the RowState property, and executes the required INSERT, UPDATE, or DELETE statements iteratively for each row, based on the order of the indexes configured in the DataSet. 例如,Update 可能会执行 DELETE 语句,后跟 INSERT 语句,然后执行另一 DELETE 语句,因为 DataTable中的行的顺序。For example, Update might execute a DELETE statement, followed by an INSERT statement, and then another DELETE statement, because of the ordering of the rows in the DataTable.

请注意,这些语句不作为批处理执行;每一行都单独更新。Be aware that these statements are not performed as a batch process; each row is updated individually. 如果必须控制语句类型的顺序(例如,在更新之前插入),则应用程序可以调用 GetChanges 方法。An application can call the GetChanges method if you must control the sequence of statement types (for example, INSERTs before UPDATEs). 有关详细信息,请参阅用 Dataadapter 更新数据源For more information, see Updating Data Sources with DataAdapters.

如果尚未指定 INSERT、UPDATE 或 DELETE 语句,Update 方法将生成一个异常。If INSERT, UPDATE, or DELETE statements have not been specified, the Update method generates an exception. 不过,如果设置 .NET Framework 数据提供程序的 SelectCommand 属性,则可以创建 SqlCommandBuilderOleDbCommandBuilder 对象以自动为单表更新生成 SQL 语句。However, you can create a SqlCommandBuilder or OleDbCommandBuilder object to automatically generate SQL statements for single-table updates if you set the SelectCommand property of a .NET Framework data provider. 然后,CommandBuilder 将生成未设置的任何其他 SQL 语句。Then, any additional SQL statements that you do not set are generated by the CommandBuilder. 此代逻辑要求密钥列信息存在于 DataSet中。This generation logic requires key column information to be present in the DataSet. 有关详细信息,请参阅通过 Commandbuilder 生成命令For more information see Generating Commands with CommandBuilders.

在执行更新之前,Update 方法从第一个映射中列出的表中检索行。The Update method retrieves rows from the table listed in the first mapping before performing an update. 然后,Update 使用 UpdatedRowSource 属性的值更新该行。The Update then updates the row using the value of the UpdatedRowSource property. 将忽略返回的任何其他行。Any additional rows returned are ignored.

将任何数据加载回 DataSet后,将引发 OnRowUpdated 事件,从而允许用户检查已协调的 DataSet 行和该命令返回的任何输出参数。After any data is loaded back into the DataSet, the OnRowUpdated event is raised, allowing the user to inspect the reconciled DataSet row and any output parameters returned by the command. 成功更新行后,将接受对该行所做的更改。After a row updates successfully, the changes to that row are accepted.

使用 Update时,执行顺序如下所示:When using Update, 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,则将第一个返回的结果置于 DataRow中。If the command is set to FirstReturnedRecord, then the first returned result is put in the DataRow.

  5. 如果有输出参数,则将它们放在 DataRow中。If there are output parameters, they are put in the DataRow.

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

  7. 调用 AcceptChangesAcceptChanges is called.

IDataAdapter 关联的每个命令通常都具有与之关联的参数集合。Each command associated with the IDataAdapter usually has a parameter collection associated with it. 通过 SourceColumnSourceVersion .NET Framework 数据提供程序的 Parameter 类的属性,将参数映射到当前行。Parameters are mapped to the current row through the SourceColumn and SourceVersion properties of a .NET Framework data provider's Parameter class. SourceColumnIDataAdapter 为获取当前行的参数值而引用的 DataTable 列。SourceColumn refers to a DataTable column that the IDataAdapter references to obtain parameter values for the current row.

在应用任何表映射之前,SourceColumn 引用未映射的列名称。SourceColumn refers to the unmapped column name before any table mappings have been applied. 如果 SourceColumn 引用不存在的列,则执行的操作取决于下列 MissingMappingAction 值之一。If SourceColumn refers to a nonexistent column, the action taken depends on one of the following MissingMappingAction values.

枚举值Enumeration Value 执行的操作Action Taken
MissingMappingAction.Passthrough 如果不存在任何映射,请使用 DataSet 中的源列名称和表名称。Use the source column names and table names in the DataSet if no mapping is present.
MissingMappingAction.Ignore 生成一个 SystemExceptionA SystemException is generated. 当显式设置映射时,缺少输入参数的映射通常是由错误引起的。When the mappings are explicitly set, a missing mapping for an input parameter is usually caused by an error.
MissingMappingAction.Error 生成一个 SystemExceptionA SystemException is generated.

SourceColumn 属性还用于将输出或输入/输出参数的值映射回 DataSetThe SourceColumn property is also used to map the value for output or input/output parameters back to the DataSet. 如果引用不存在的列,则会生成异常。An exception is generated if it refers to a nonexistent column.

.NET Framework 数据提供程序的 Parameter 类的 SourceVersion 属性确定是使用列值的 OriginalCurrent还是 Proposed 版本。The SourceVersion property of a .NET Framework data provider's Parameter class determines whether to use the Original, Current, or Proposed version of the column value. 此功能经常用于在 UPDATE 语句的 WHERE 子句中包含原始值,以检查是否存在开放式并发冲突。This capability is frequently used to include original values in the WHERE clause of an UPDATE statement to check for optimistic concurrency violations.


如果在更新行时出现错误,则会引发异常并中止执行更新。If an error occurs while updating a row, an exception is thrown and execution of the update is discontinued. 若要在遇到错误时继续执行更新操作而不生成异常,请在调用 Update之前将 ContinueUpdateOnError 属性设置为 trueTo continue the update operation without generating exceptions when an error is encountered, set the ContinueUpdateOnError property to true before calling Update. 您还可以在 DataAdapter 的 RowUpdated 事件内每行响应错误。You may also respond to errors on a per-row basis within the RowUpdated event of a DataAdapter. 若要在 RowUpdated 事件中继续执行更新操作而不生成异常,请将 RowUpdatedEventArgsStatus 属性设置为 "Continue"。To continue the update operation without generating an exception within the RowUpdated event, set the Status property of the RowUpdatedEventArgs to Continue.