OleDbDataAdapter.DeleteCommand 属性
定义
重要
一些信息与预发行产品相关,相应产品在发行之前可能会进行重大修改。 对于此处提供的信息,Microsoft 不作任何明示或暗示的担保。
获取或设置 SQL 语句或存储过程,用于从数据集中删除记录。
public:
property System::Data::OleDb::OleDbCommand ^ DeleteCommand { System::Data::OleDb::OleDbCommand ^ get(); void set(System::Data::OleDb::OleDbCommand ^ value); };
public System.Data.OleDb.OleDbCommand DeleteCommand { get; set; }
public System.Data.OleDb.OleDbCommand? DeleteCommand { get; set; }
[System.Data.DataSysDescription("DbDataAdapter_DeleteCommand")]
public System.Data.OleDb.OleDbCommand DeleteCommand { get; set; }
member this.DeleteCommand : System.Data.OleDb.OleDbCommand with get, set
[<System.Data.DataSysDescription("DbDataAdapter_DeleteCommand")>]
member this.DeleteCommand : System.Data.OleDb.OleDbCommand with get, set
Public Property DeleteCommand As OleDbCommand
属性值
在 OleDbCommand 过程中使用的 Update(DataSet),用以删除数据源中与 DataSet 中已删除的行相对应的记录。
- 属性
示例
以下示例创建并 OleDbDataAdapter 设置 SelectCommand 和 DeleteCommand 属性。 它假定你已经创建了一个 OleDbConnection 对象。
public static OleDbDataAdapter CreateCustomerAdapter(
OleDbConnection connection)
{
OleDbDataAdapter dataAdapter = new OleDbDataAdapter();
OleDbCommand command;
OleDbParameter parameter;
// Create the SelectCommand.
command = new OleDbCommand("SELECT CustomerID FROM Customers " +
"WHERE Country = ? AND City = ?", connection);
command.Parameters.Add("Country", OleDbType.VarChar, 15);
command.Parameters.Add("City", OleDbType.VarChar, 15);
dataAdapter.SelectCommand = command;
// Create the DeleteCommand.
command = new OleDbCommand(
"DELETE * FROM Customers WHERE CustomerID = ?",
connection);
parameter = command.Parameters.Add(
"CustomerID", OleDbType.Char, 5, "CustomerID");
parameter.SourceVersion = DataRowVersion.Original;
dataAdapter.DeleteCommand = command;
return dataAdapter;
}
Public Shared Function CreateCustomerAdapter( _
connection As OleDbConnection) As OleDbDataAdapter
Dim dataAdapter As New OleDbDataAdapter()
Dim command As OleDbCommand
Dim parameter As OleDbParameter
' Create the SelectCommand.
command = New OleDbCommand("SELECT CustomerID FROM Customers " & _
"WHERE Country = ? AND City = ?", connection)
command.Parameters.Add("Country", OleDbType.VarChar, 15)
command.Parameters.Add("City", OleDbType.VarChar, 15)
dataAdapter.SelectCommand = command
' Create the DeleteCommand.
command = New OleDbCommand( _
"DELETE * FROM Customers WHERE CustomerID = ?", _
connection)
parameter = command.Parameters.Add( _
"CustomerID", OleDbType.Char, 5, "CustomerID")
parameter.SourceVersion = DataRowVersion.Original
dataAdapter.DeleteCommand = command
Return dataAdapter
End Function
注解
在此期间 Update,如果未设置此属性并且主键信息存在于该属性中 DataSet, DeleteCommand 则可以自动生成 SelectCommand 此属性并使用此属性 OleDbCommandBuilder。 然后,未设置的任何其他命令都由该命令 OleDbCommandBuilder生成。 此生成逻辑要求关键列信息存在于 .DataSet 有关详细信息,请参阅使用 CommandBuilders 生成命令。
分配给以前创建的OleDbCommand时DeleteCommand,OleDbCommand不会克隆。 维护 DeleteCommand 对以前创建 OleDbCommand 对象的引用。