Row Num Is Not Displaying Any Rows When Using Between Keyword

row num is not displaying any rows when using between keyword

Oracle rownum starts at 1, so you will never get the first rownum if you say between 2 and N.

It takes a row to "initiate" the rownum pseudocolumn sequence, so by eliminating rownum 1 in your criteria, you eliminate all rownums (or every row essentially has rownum 0).

Look at it like this. You don't get a ROWNUM until the database returns a row to you. The first row of any criteria will always be ROWNUM 1.

Now, the trick you can use is to use a subquery. Each subquery will have its own rownum, and if you alias it to another column name, you can preserve it into outer queries, and treat it however you like. So if you are looking to implement paging of a result set, you would normally alias rownum from inner results as rownum_ to an outer subquery to limit with BETWEEN.

select * from 
  (select t.*, rownum as rownum_ from t)
where rownum_ between 2 and 6

But note, that the outer result set will have its own rownum, so you could do:

select t2.*, rownum from 
  (select a, b, rownum as rownum_ from t) t2
where rownum_ between 2 and 6

You will see rownum on the final result still starts at 1, but your inner result will have rownum_ starting at 2.

Rownum between clause not working - Oracle

rownum is incremented as the result set is generated. If the value "1" is never generated, then "2" is never generated.

Because you want to return the row number, I would recommend using row_number():

select seqnum, user_id
from (select t1.*, row_number() over (order by ?) as seqnum
      from table1 t1
     ) t1
where seqnum between 2 and 4;

The ? is for the column that specifies the order of the result set.

SQL tables represent unordered sets. So your original query is functionally equivalent to:

select (1 + rownum), userid
from table1
where rownum <= 3;

Because the ordering is not specified. With a specified ordering, you can use row_number().

In Oracle 12C+, you can also express this as:

select rownum, userid
from table1
offset 1 row fetch first 3 rows only;

Using rownum with the combination of between keyword

If I had to guess, I'd say that the reason you're not seeing what you expect (in addition to having the operators backwards, as pointed out by @diagonalbatman) is that you didn't tell the database what order you wanted the rows in. You're essentially telling the database to return any 5 rows. You can't even be sure that this query will always return the same five rows. Any time you're getting a subset like this, you should use an order by clause in the innermost query, so that the sort is applied before the rownum values are issued:

SELECT *
FROM   (SELECT ROWNUM rnum, a.*
        FROM   (SELECT   *
                FROM     emp
                ORDER BY emp_id) a
        WHERE  ROWNUM <= 8)
WHERE  rnum >= 4;

Using rownum in sub query on oracle 11

Syntax is a bit different - you need an extra subquery so it would need to be more like ...
where customerId IN (select * from (select custId from Orders where orderStatus = 'S' and orderCity = 'Amsterdam' and ORDER BY custId DESC) where rownum <=10)

You wouldn't need the extra subquery if you didn't have the order by clause

For ref see https://docs.oracle.com/cd/B19306_01/server.102/b14200/pseudocolumns009.htm#:~:text=For%20each%20row%20returned%20by,has%202%2C%20and%20so%20on.

Difference when using ROWNUM

The issue is that you are filtering in the same query that the ROWNUM is being generated. Hence the reason you must have a subquery generate the rownum first and then apply the filtering. Why the BETWEEN works fine is probably some nuance of how the engine processes the query, but I would be wary that it might not consistently give you correct results. So it's not a matter of performance as it is a matter of actually getting correct results.

This article explains why you have to put the greater than outside the subquery:
http://download.oracle.com/docs/cd/B19306_01/server.102/b14200/pseudocolumns009.htm

SELECT * FROM employees
    WHERE ROWNUM > 1;

"The first row fetched is assigned a ROWNUM of 1 and makes the condition false. The second row to be fetched is now the first row and is also assigned a ROWNUM of 1 and makes the condition false. All rows subsequently fail to satisfy the condition, so no rows are returned."

Error on Partition over row number

Remove as rows. It is not proper syntax for the table/query alias. It is syntax for column alias.

select *
from (
   select T.*, 
          row_number() over (partition by DIS_COL order by COL_2) as row_number --ORDER BY FIELD DETERMINES WHICH ROW IS THE FIRST ROW AND THUS WHICH ONE IS SELECTED.
   from MY_TABLE t
   ) 
where row_number = 1
AND (CRITERIA_COL = 'CRIT_1'
OR CRITERIA_COL_2 = 'CRIT_2');

Selecting the second row of a table using rownum

To explain this behaviour, we need to understand how Oracle processes
ROWNUM. When assigning ROWNUM to a row, Oracle starts at 1 and
only increments the value when a row is selected; that is, when all
conditions in the WHERE clause are met. Since our condition requires
that ROWNUM is greater than 2, no rows are selected and ROWNUM is
never incremented beyond 1.

The bottom line is that conditions such as the following will work as
expected.

.. WHERE rownum = 1;

.. WHERE rownum <= 10;

While queries with these conditions will always return zero rows.

.. WHERE rownum = 2;

.. WHERE rownum > 10;

Quoted from Understanding Oracle rownum

You should modify you query in this way in order to work:

select empno
from
    (
    select empno, rownum as rn 
    from (
          select empno
          from emp
          order by sal desc
          )
    )
where rn=2;

EDIT: I've corrected the query to get the rownum after the order by sal desc

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