分页查询相关知识：一篇文章让你豁然开朗

select rownum,kname,sal from k

select * FROM (select rownum rn,sal,kname from k )where  rn      between 6 and 8

如果需要查询工资6-8的员工信息，先排序，在编号，在查询。
select kname,sal,depino from order by sal desc
select rownum rn,l.* from(select kname,sal,depino from order by sal desc) l
select * from (select rownum rn,l.* from(select kname,sal,depino from k order by sal desc)l)where rn between 6 and 8

select * from 
(select rownum rn,l.* from 
(select kname,sal,id from k order by sal desc) l where rownum<=8)
where rn >6

select * from 
(select rownum rn,l.* from 
(select kname,sal,id from k order by sal desc) l where rownum<=end)
where rn >start

select id,kname,sal,
decode(depino,
       10,sal*1.2,
       20,sal*1.3,
       30,sal*1.5,
       sal) end
from k

select depino,kname,sal,
 case depino when 10 then sal*1.2
              when 20 then sal*1.4
              else sal end
              bonus
from k

select count(*),
 decode (depino,
        10,100,
        20,100,
        200 )
 from k
 group by decode(
        depino,
        10,100,
        20,100,
        200)

select depino,kname from k
order by
decode (depino,
10,1
20,2
30)

select kname,sal,depino,row_number() over(
partition by depino
order by sal desc
) rank
from k

select kname,sal,depino,rank() over(
partition by depino
order by sal desc
) rank
from k

select kname,sal,depino,dense_rank() over(
partition by depino
order by sal desc
 ) rank
from k

create table sales_tab(
year_id number not null,
month_id number not null,
day_id number not null,
sales_value number(10,2)not null
)
insert into sales_tab
select trunc(dbms_random.value(2021,2022))AS year_id,
trunc(dbms_random.value(1,13))as month_id,
trunc(dbms_random.value(1,32))as day_id,
round(dbms_random.value(1,100),2)as sales_value
from dual
connect by level<=100