OleDbDataAdapter.SelectCommand Proprietà

  • Riferimento

Definizione

Spazio dei nomi:
System.Data.OleDb
Assembly:
System.Data.OleDb.dll
Assembly:
System.Data.dll
Pacchetto:
System.Data.OleDb v8.0.1
Pacchetto:
System.Data.OleDb v9.0.0-rc.2.24473.5
Origine:
OleDbDataAdapter.cs
Origine:
OleDbDataAdapter.cs

Ottiene o imposta un'istruzione SQL o una stored procedure per selezionare record nell'origine dati.

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

Valore della proprietà

OleDbCommand

Oggetto OleDbCommand utilizzato durante l'applicazione del metodo Fill(DataSet) per selezionare record da un'origine dati e collocarli nell'oggetto DataSet.

Attributi
DataSysDescriptionAttribute

Esempio

Nell'esempio seguente viene creato un oggetto OleDbDataAdapter e vengono impostate le SelectCommand proprietà e InsertCommand . Presuppone che sia già stato creato un OleDbConnection oggetto.

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, l'oggetto OleDbCommand non viene clonato. Mantiene SelectCommand un riferimento all'oggetto creato OleDbCommand in precedenza.

Se non SelectCommand viene restituita alcuna riga, non vengono aggiunte tabelle all'oggetto DataSete non viene generata alcuna eccezione.

Si applica a

Vedi anche