IDbDataAdapter.SelectCommand 屬性
定義
重要
部分資訊涉及發行前產品,在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊,不做任何明確或隱含的瑕疵擔保。
取得或設定一個用於選擇資料來源記錄的 SQL 陳述式。
public:
property System::Data::IDbCommand ^ SelectCommand { System::Data::IDbCommand ^ get(); void set(System::Data::IDbCommand ^ value); };
public System.Data.IDbCommand SelectCommand { get; set; }
member this.SelectCommand : System.Data.IDbCommand with get, set
Public Property SelectCommand As IDbCommand
屬性值
在 IDbCommand 期間 Update(DataSet) ,會用來從資料來源中選取記錄,以便放入資料集中。
範例
以下範例建立繼承 OleDbDataAdapter 類別的實例,並設定 SelectCommand 和 InsertCommand 屬性。 它假設你已經建立了 OleDbConnection 一個物件。
public static OleDbDataAdapter CreateCustomerAdapter(
OleDbConnection connection)
{
OleDbDataAdapter adapter = new OleDbDataAdapter();
OleDbCommand command;
// Create the SelectCommand.
command = new OleDbCommand("SELECT * FROM Customers " +
"WHERE Country = ? AND City = ?", connection);
command.Parameters.Add("Country", OleDbType.VarChar, 15);
command.Parameters.Add("City", OleDbType.VarChar, 15);
adapter.SelectCommand = command;
// Create the InsertCommand.
command = new OleDbCommand(
"INSERT INTO Customers (CustomerID, CompanyName) " +
"VALUES (?, ?)", connection);
command.Parameters.Add(
"CustomerID", OleDbType.Char, 5, "CustomerID");
command.Parameters.Add(
"CompanyName", OleDbType.VarChar, 40, "CompanyName");
adapter.InsertCommand = command;
return adapter;
}
Public Shared Function CreateCustomerAdapter( _
connection As OleDbConnection) As OleDbDataAdapter
Dim adapter As New OleDbDataAdapter()
Dim command As OleDbCommand
' Create the SelectCommand.
command = New OleDbCommand("SELECT * FROM Customers " & _
"WHERE Country = ? AND City = ?", connection)
command.Parameters.Add("Country", OleDbType.VarChar, 15)
command.Parameters.Add("City", OleDbType.VarChar, 15)
adapter.SelectCommand = command
' Create the InsertCommand.
command = New OleDbCommand( _
"INSERT INTO Customers (CustomerID, CompanyName) " & _
"VALUES (?, ?)", connection)
command.Parameters.Add( _
"CustomerID", OleDbType.Char, 5, "CustomerID")
command.Parameters.Add( _
"CompanyName", OleDbType.VarChar, 40, "CompanyName")
adapter.InsertCommand = command
Return adapter
End Function
備註
當 SelectCommand 被指派給先前建立 IDbCommand的 時,則 IDbCommand 不會被複製。 它 SelectCommand 會維持對先前建立 IDbCommand 物件的參考。
若 未 SelectCommand 回傳任何列,則不會新增資料表到 DataSet,且不會提出例外。