<STRONG><FONT size=5><FONT size=3>在执行时发生错误，请指教

<BR>ORA-01453: SET TRANSACTION

</FONT> </FONT></STRONG> <H2><FONT size=3>代碼如下：</FONT></H2> <P>using(OracleConnection conn = new OracleConnection(new ConnDBString.ConnDBStringConfig()["4"]))<BR>&nbsp;&nbsp;&nbsp;{<BR>&nbsp;&nbsp;&nbsp;&nbsp;conn.Open();<BR>&nbsp;&nbsp;&nbsp;&nbsp;OracleTransaction trans = conn.BeginTransaction(IsolationLevel.ReadCommitted);<BR>&nbsp;&nbsp;&nbsp;&nbsp;<BR>&nbsp;&nbsp;&nbsp;&nbsp;OracleCommand cmd = new OracleCommand("SELECT * FROM DUAL");<BR>&nbsp;&nbsp;&nbsp;&nbsp;cmd.Connection = conn;<BR>&nbsp;&nbsp;&nbsp;&nbsp;cmd.Transaction = trans;<BR>&nbsp;&nbsp;&nbsp;&nbsp;try<BR>&nbsp;&nbsp;&nbsp;&nbsp;{<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;cmd.ExecuteNonQuery();<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;cmd.CommandText = "SELECT * FROM DUAL";<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;cmd.ExecuteNonQuery();<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;trans.Commit();<BR>&nbsp;&nbsp;&nbsp;&nbsp;}<BR>&nbsp;&nbsp;&nbsp;&nbsp;catch(Exception ex)<BR>&nbsp;&nbsp;&nbsp;&nbsp;{<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;trans.Rollback();<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;throw new Exception(ex.Message);<BR>&nbsp;&nbsp;&nbsp;&nbsp;}&nbsp;&nbsp;&nbsp;</P> <P>}</P>