Oracle与DB2、MySQL取前10条记录的对比

row_number() over ( partition by col1 order by col2 )
比如想取出100-150条记录,按照tname排序

select tname,tabtype from (
select tname,tabtype,row_number() over ( order by tname ) rn from tab
)
where rn between 100 and 150;

select tname,tabtype from (
select tname,tabtype,rownum rn from tab where rownum <= 150
)
where rn >= 100;

create table mynumber(id int,name varchar(10));
insert into mynumber values(1,'no1');
insert into mynumber values(2,'no2');
insert into mynumber values(3,'no3');
insert into mynumber values(4,'no4');
insert into mynumber values(5,'no5');
insert into mynumber values(5,'no6');
insert into mynumber values(6,'no7');
insert into mynumber values(7,'no8');
insert into mynumber values(8,'no9');
insert into mynumber values(9,'no10');
insert into mynumber values(9,'no11');
insert into mynumber values(9,'no12');
insert into mynumber values(10,'no13');
insert into mynumber values(10,'no14');
insert into mynumber values(10,'no15');
insert into mynumber values(11,'no16');
insert into mynumber values(12,'no17');
insert into mynumber values(13,'no18');

select id,name,RANK() over ( order by id ) case1,
DENSE_RANK() over ( order by id ) case2,
row_number() over ( order by id ) case3 from mynumber;

select id,name from mynumber where id in 
(select id from (select distinct id 
from mynumber) tt where rownum<=10);

select * from (select id,name,RANK() 
over ( order by id ) case1,DENSE_RANK() 
over ( order by id ) case2,row_number() 
over ( order by id ) case3 from mynumber)
tt where case1<=10;
select * from (select id,name,RANK() over 
( order by id ) case1,DENSE_RANK() over 
( order by id ) case2,row_number() over 
( order by id ) case3 from mynumber) 
tt where case1 between 5 and 10;

select * from mynumber where id in
(select id from mynumber where rownum <=10);

select * from (select id,name,RANK() 
over ( order by id ) case1,DENSE_RANK() 
over ( order by id ) case2,row_number() 
over ( order by id ) case3 from mynumber) 
tt where case2<=10;
select * from (select id,name,RANK() 
over ( order by id ) case1,DENSE_RANK() 
over ( order by id ) case2,row_number() 
over ( order by id ) case3 from mynumber) 
tt where case2 between 5 and 10;