public override bool Equals(object obj)
        {
            if (obj == null)
            {
                return(false);
            }

            SQLiteSortItem dst = obj as SQLiteSortItem;

            if (dst == null)
            {
                return(false);
            }

            if (!RefCompare.Compare(_expr, dst._expr))
            {
                return(false);
            }

            if (_order != dst._order)
            {
                return(false);
            }

            return(true);
        }
        public virtual object Clone()
        {
            SQLiteExpression expr = null;

            if (_expr != null)
            {
                expr = (SQLiteExpression)_expr.Clone();
            }

            SQLiteSortItem res = new SQLiteSortItem();

            res._expr  = expr;
            res._order = _order;
            return(res);
        }