SqlCeCommand.ExecuteReader 方法 (CommandBehavior)
藉由使用其中一個 CommandBehavior 值,將 CommandText 傳送到 Connection 並建立 SqlCeDataReader。
命名空間: System.Data.SqlServerCe
組件: System.Data.SqlServerCe (在 System.Data.SqlServerCe.dll 中)
語法
'宣告
Public Function ExecuteReader ( _
behavior As CommandBehavior _
) As SqlCeDataReader
'用途
Dim instance As SqlCeCommand
Dim behavior As CommandBehavior
Dim returnValue As SqlCeDataReader
returnValue = instance.ExecuteReader(behavior)
public SqlCeDataReader ExecuteReader(
CommandBehavior behavior
)
public:
SqlCeDataReader^ ExecuteReader(
CommandBehavior behavior
)
member ExecuteReader :
behavior:CommandBehavior -> SqlCeDataReader
public function ExecuteReader(
behavior : CommandBehavior
) : SqlCeDataReader
參數
- behavior
型別:System.Data.CommandBehavior
其中一個 CommandBehavior 值。
傳回值
型別:System.Data.SqlServerCe.SqlCeDataReader
SqlCeDataReader 物件。
例外狀況
例外狀況 | 條件 |
---|---|
InvalidOperationException | 如果某項交易內容與原本連接登記的內容不同,便無法在那個交易內容中執行命令。 |
備註
SqlCeDataReader 支援可有效讀取大型二進位值的特殊模式。如需詳細資訊,請參閱 CommandBehavior 的 SequentialAccess 設定。
當 SqlCeDataReader 在使用中時,相關聯的 SqlCeConnection 會忙於服務 SqlCeDataReader。在這種狀態下,在呼叫 SqlCeDataReader 的 Close 方法之前,都只能在 SqlCeConnection 上執行 Close 作業。
範例
下列範例會建立 SqlCeCommand,然後透過傳遞 SQL SELECT 陳述式和 SqlCeConnection 物件來執行它。CommandBehavior 會設定為 CloseConnection。
Dim conn As New SqlCeConnection(connString)
Dim cmd As New SqlCeCommand("SELECT * FROM myTable", conn)
cmd.Connection.Open()
Dim rdr As SqlCeDataReader = Nothing
Try
' Execute the reader; make sure you alway close the
' reader after you're done using it (ideally in the finally block)
'
rdr = cmd.ExecuteReader(CommandBehavior.CloseConnection)
While rdr.Read()
Console.WriteLine(rdr.GetString(0))
End While
Finally
' Closing the reader will also close the associated connection
'
rdr.Close()
End Try
SqlCeConnection conn = new SqlCeConnection(connString);
SqlCeCommand cmd = new SqlCeCommand("SELECT * FROM myTable", conn);
cmd.Connection.Open();
SqlCeDataReader rdr = null;
try
{
// Execute the reader; make sure you alway close the
// reader after you're done using it (ideally in the finally block)
//
rdr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
while (rdr.Read())
{
Console.WriteLine(rdr.GetString(0));
}
}
finally
{
// Closing the reader will also close the associated connection
//
rdr.Close();
}