IDbDataAdapter.SelectCommand Propiedad

Definición

Espacio de nombres:

System.Data

Ensamblado:

System.Data.dll

Obtiene o establece una instrucción SQL que se usa para seleccionar registros en el origen de datos.

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

Valor de propiedad

IDbCommand

que IDbCommand se usa durante Update(DataSet) para seleccionar registros del origen de datos para colocarlos en el conjunto de datos.

Ejemplos

En el ejemplo siguiente se crea una instancia de la clase heredada OleDbDataAdapter y se establecen las SelectCommand propiedades y InsertCommand . Se supone que ya ha creado un OleDbConnection objeto .

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

Comentarios

Cuando SelectCommand se asigna a un objeto creado IDbCommandanteriormente, no IDbCommand se clona. SelectCommand mantiene una referencia al objeto creado IDbCommand anteriormente.

SelectCommand Si no devuelve ninguna fila, no se agrega ninguna tabla a DataSety no se genera ninguna excepción.