错误记录

数据控制：

SqlConnection conn = db.GetConnection();
SqlTransaction trans = conn.BeginTransaction();

foreach(CartInfo cartItem in cartItems)
                   {
                       insertSp[1].Value=cartItem.bookid;
                       insertSp[2].Value=cartItem.price;
                       insertSp[3].Value=cartItem.itemname;
                       insertSp[4].Value=cartItem.quantity;
                       db.ExecuteNonQuery(trans,CommandType.StoredProcedure,"InsertCartItems",insertSp);

                    //不能将trans.Commit()放在foreach内部，因为commit会结束事务。
                   }
                   trans.Commit();