一个简单的数据库访问问题,请大侠们多帮忙呀

Question

System.Data.OleDb.OleDbTransaction trans=null;
System.Data.OleDb.OleDbConnection conn1=baseclass.basedata.open("dictdb");
  conn1.Open();
trans = conn1.BeginTransaction(IsolationLevel.ReadCommitted);
 try
  {
System.Data.OleDb.OleDbCommand command=new System.Data.OleDb.OleDbCommand();
command.CommandText="delete from service_state where id='"+sid+"'";
command.Transaction=trans;
command.Connection=conn1;
command.ExecuteNonQuery();
trans.Commit();
  }
  catch
  {
trans.Rollback();
   }
  finally
   {
conn1.Close();
   }