如何使用
ROW_NUMBER：
SQL小提琴
WITH Cte AS( SELECt *, RnAsc = ROW_NUMBER() OVER(PARTITION BY [group] ORDER BY val), RnDesc = ROW_NUMBER() OVER(PARTITION BY [group] ORDER BY val DESC) FROM tbl)SELECt id, [group], val, start, [end]FROM CteWHERe RnAsc = 1 OR RnDesc = 1ORDER BY [group], val
