Introduction to advanced Oracle Functions

-- Select deptno, count (1), sum (count (1) over (order by deptno DESC rows between unbounded preceding and unbounded following) as AAA, sum (count (1) over () as AAAA from EMP group by deptno; -- select empno, Sal, rank () over (order by Sal DESC) as AA, dense_rank () over (order by Sal DESC) as AAA, row_number () over (order by Sal DESC) as AAAA from EMP; -- sort, get the first and last select Min (empno) Keep (dense_rank first order by Sal DESC) as AA, min (empno) Keep (dense_rank last order by Sal DESC) as AAA from EMP; -- percentage select months, round (ratio_to_report (sum (tot_sales) over (), 2) as AAA from orders group by months -- evenly divided into five levels: Select empno, ntile (5) over (order by Sal DESC) as AA from EMP; -- select months, sum (tot_sales) monthly_sales, lag (sum (tot_sales), 2) over (order by months) prev_month_sales from orders group by months;