How do I limit the number of rows returned by an Oracle query after ordering?

Question

Is there a way to make an Oracle query behave like it contains a MySQL limit clause?

In MySQL, I can do this:

Answer 1

In case of SQL-Developer, it automatically fetches only first 50 rows. And if we scroll down, it fetches another 50 rows and so on !

Hence we dont need to define, in case of sql-developer tool !

Answer 2

(untested) something like this may do the job

WITH
base AS
(
    select *                   -- get the table
    from sometable
    order by name              -- in the desired order
),
twenty AS
(
    select *                   -- get the first 30 rows
    from base
    where rownum < 30
    order by name              -- in the desired order
)
select *                       -- then get rows 21 .. 30
from twenty
where rownum > 20
order by name                  -- in the desired order

There is also the analytic function rank, that you can use to order by.

Answer 3

select * FROM (SELECT 
   ROW_NUMBER() OVER (ORDER BY sal desc),* AS ROWID, 
 FROM EMP ) EMP  where ROWID=5

greater then values find out

select * FROM (SELECT 
       ROW_NUMBER() OVER (ORDER BY sal desc),* AS ROWID, 
     FROM EMP ) EMP  where ROWID>5

less then values find out

select * FROM (SELECT 
       ROW_NUMBER() OVER (ORDER BY sal desc),* AS ROWID, 
     FROM EMP ) EMP  where ROWID=5

Answer 4

For each row returned by a query, the ROWNUM pseudocolumn returns a number indicating the order in which Oracle selects the row from a table or set of joined rows. The first row selected has a ROWNUM of 1, the second has 2, and so on.

  SELECT * FROM sometable1 so
    WHERE so.id IN (
    SELECT so2.id from sometable2 so2
    WHERE ROWNUM <=5
    )
    AND ORDER BY so.somefield AND ROWNUM <= 100 

I have implemented this in oracle server 11.2.0.1.0

Answer 5

Less SELECT statements. Also, less performance consuming. Credits to: anibal@upf.br

SELECT *
    FROM   (SELECT t.*,
                   rownum AS rn
            FROM   shhospede t) a
    WHERE  a.rn >= in_first
    AND    a.rn <= in_first;