OleDbDataAdapter.SelectCommand OleDbDataAdapter.SelectCommand OleDbDataAdapter.SelectCommand OleDbDataAdapter.SelectCommand Property

Definizione

Ottiene o imposta un'istruzione SQL o una stored procedure per selezionare record nell'origine dati.Gets or sets an SQL statement or stored procedure used to select records in the data source.

public:
 property System::Data::OleDb::OleDbCommand ^ SelectCommand { System::Data::OleDb::OleDbCommand ^ get(); void set(System::Data::OleDb::OleDbCommand ^ value); };
[System.Data.DataSysDescription("DbDataAdapter_SelectCommand")]
public System.Data.OleDb.OleDbCommand SelectCommand { get; set; }
member this.SelectCommand : System.Data.OleDb.OleDbCommand with get, set
Public Property SelectCommand As OleDbCommand

Valore della proprietà

Oggetto OleDbCommand utilizzato durante l'applicazione del metodo Fill(DataSet) per selezionare record da un'origine dati e collocarli nell'oggetto DataSet.An OleDbCommand that is used during Fill(DataSet) to select records from data source for placement in the DataSet.

Esempi

Nell'esempio seguente viene creato OleDbDataAdapter un oggetto e SelectCommand vengono InsertCommand impostate le proprietà e.The following example creates an OleDbDataAdapter and sets the SelectCommand and InsertCommand properties. Si presuppone che sia già stato creato un OleDbConnection oggetto.It assumes that you have already created an OleDbConnection object.

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

Commenti

Quando SelectCommand viene assegnato a un oggetto creato OleDbCommandin precedenza OleDbCommand , non viene clonato.When SelectCommand is assigned to a previously created OleDbCommand, the OleDbCommand is not cloned. Mantiene un riferimento all'oggetto creato OleDbCommand in precedenza. SelectCommandThe SelectCommand maintains a reference to the previously created OleDbCommand object.

Se non DataSetrestituisce righe, non viene aggiunta alcuna tabella a e non viene generata alcuna eccezione. SelectCommandIf the SelectCommand returns no rows, no tables are added to the DataSet, and no exception is raised.

Si applica a

Vedi anche