DbDataAdapter.UpdateCommand 属性
定义
获取或设置用于更新数据源中的记录的命令。Gets or sets a command used to update records in the data source.
public:
property System::Data::Common::DbCommand ^ UpdateCommand { System::Data::Common::DbCommand ^ get(); void set(System::Data::Common::DbCommand ^ value); };
[System.ComponentModel.Browsable(false)]
public System.Data.Common.DbCommand? UpdateCommand { get; set; }
[System.ComponentModel.Browsable(false)]
public System.Data.Common.DbCommand UpdateCommand { get; set; }
[<System.ComponentModel.Browsable(false)>]
member this.UpdateCommand : System.Data.Common.DbCommand with get, set
member this.UpdateCommand : System.Data.Common.DbCommand with get, set
Public Property UpdateCommand As DbCommand
属性值
在 IDbCommand 过程中使用的 Update(DataSet),它针对数据集中已修改的行更新数据源中的记录。A IDbCommand used during Update(DataSet) to update records in the data source for modified rows in the data set.
- 属性
示例
下面的示例创建派生类 OleDbDataAdapter 并设置其一些属性。The following example creates the derived class OleDbDataAdapter and sets some of its properties.
public static OleDbDataAdapter CreateCustomerAdapter(OleDbConnection conn)
{
OleDbDataAdapter da = new OleDbDataAdapter();
OleDbCommand cmd;
OleDbParameter parm;
// Create the SelectCommand.
cmd = new OleDbCommand("SELECT * FROM Customers " +
"WHERE Country = @Country AND City = @City", conn);
cmd.Parameters.Add("@Country", OleDbType.VarChar, 15);
cmd.Parameters.Add("@City", OleDbType.VarChar, 15);
da.SelectCommand = cmd;
// Create the UpdateCommand.
cmd = new OleDbCommand("UPDATE Customers SET CustomerID = @CustomerID, CompanyName = @CompanyName " +
"WHERE CustomerID = @oldCustomerID", conn);
cmd.Parameters.Add("@CustomerID", OleDbType.Char, 5, "CustomerID");
cmd.Parameters.Add("@CompanyName", OleDbType.VarChar, 40, "CompanyName");
parm = cmd.Parameters.Add("@oldCustomerID", OleDbType.Char, 5, "CustomerID");
parm.SourceVersion = DataRowVersion.Original;
da.UpdateCommand = cmd;
return da;
}
Public Shared Function CreateCustomerAdapter(conn As OleDbConnection) As OleDbDataAdapter
Dim da As New OleDbDataAdapter()
Dim cmd As OleDbCommand
Dim parm As OleDbParameter
' Create the SelectCommand.
cmd = New OleDbCommand("SELECT * FROM Customers " & _
"WHERE Country = @Country AND City = @City", conn)
cmd.Parameters.Add("@Country", OleDbType.VarChar, 15)
cmd.Parameters.Add("@City", OleDbType.VarChar, 15)
da.SelectCommand = cmd
' Create the UpdateCommand.
cmd = New OleDbCommand("UPDATE Customers SET CustomerID = @CustomerID, CompanyName = @CompanyName " & _
"WHERE CustomerID = @oldCustomerID", conn)
cmd.Parameters.Add("@CustomerID", OleDbType.Char, 5, "CustomerID")
cmd.Parameters.Add("@CompanyName", OleDbType.VarChar, 40, "CompanyName")
parm = cmd.Parameters.Add("@oldCustomerID", OleDbType.Char, 5, "CustomerID")
parm.SourceVersion = DataRowVersion.Original
da.UpdateCommand = cmd
Return da
End Function
注解
在过程中 Update ,如果未设置此属性,并且主键信息存在于中 DataSet ,则 UpdateCommand 将自动生成。During Update, if this property is not set and primary key information is present in the DataSet, the UpdateCommand will be automatically generated.