SQL Rownum How to Return Rows Between a Specific Range

SQL ROWNUM how to return rows between a specific range

 SELECT * from
 (
 select m.*, rownum r
 from maps006 m
 )
 where r > 49 and r < 101

How to return the rows between 20th and 30th in Oracle Sql

SELECT * 
FROM T 
ORDER BY I 
OFFSET 20 ROWS --skips 20 rows
FETCH NEXT 10 ROWS ONLY --takes 10 rows

This shows only rows 21 to 30. Take care here that you need to sort the data, otherwise you may get different results every time.

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;

How can I select rows by range?

For mysql you have limit, you can fire query as :

SELECT * FROM table limit 100` -- get 1st 100 records
SELECT * FROM table limit 100, 200` -- get 200 records beginning with row 101

For Oracle you can use rownum

See mysql select syntax and usage for limit here.

For SQLite, you have limit, offset. I haven't used SQLite but I checked it on SQLite Documentation. Check example for SQLite here.

select range with row number

There problem here is you cannot use windowed functions in the where clause. This is a consequence of the logical processing order. In short the row number is generated after everything else has been processed, including any filters you may have in your where.

You can work around this restriction using subqueries or CTEs. In this example the ROW_NUMBER is calculated in a subquery. This in turn is filtered by the main query.

Example

SELECT
    *
FROM
    (
        -- SNO will be available to outer WHERE.
        SELECT
            ROW_NUMBER() OVER (ORDER BY PrdID ASC) AS sno,
            *
        FROM
            ProductDetails 
        WHERE
            ProductDetails.UserId = 38 
    ) AS sq
WHERE
    sno BETWEEN 2000 AND 2020
;

This works because the subquery is processed in its entirety, before the results are passed to the outer query.

sql select * between exact number of rows

We can do this by multiple way.

we can do with the help of offset-fetch clause.
select * from Table_Name order by Column_Name offset 234 rows fetch next 16 rows only

it will fetch the record between 235-250. because it will skip first 234 rows and will fetch next 16 rows.

we can use simple select statement with where clause.
Select * from Table_Name where Column_Name Between 235 and 250

it will also fetch same result.

Hope it will help.

ORACLE update range of rows selecting them by rownum

Your current condition is contradictory as a value cannot be less than 10 million and more than 20 million at the same time. But even if you reversed that it still wouldn't work as you expect, because of the way - and when - rownum is set. From the documentation:

Conditions testing for ROWNUM values greater than a positive integer are always false. For example, this query returns no rows:
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.

Using rownum for this isn't ideal, but if you change your statement to:

UPDATE "STATISTICS" SET MEDIA = (CASE WHEN TB_STATISTICS.TYPE > 3 THEN 2 ELSE 1 END)
where (MEDIA IS NULL OR  MEDIA != (CASE WHEN TB_STATISTICS.TYPE > 3 THEN 2 ELSE 1 END))
and rownum < 10000000 ;

then each time you run that it will exclude the rows you've already updated, or (as a bonus) which already had the right value anyway, because they will fail the where condition; but it allows for the value to initially be null too.

You could also do this in a PL/SQL block, preferably with bulk queries and updates, perhaps something like this is you have a unique or primary key field:

declare
  type t_tab_type is table of statistics%rowtype;
  l_tab t_tab_type;
  cursor c is select * from statistics;
begin
  open c;
  loop
  fetch c bulk collect into l_tab limit 10000000;
    forall i in 1..l_tab.count
      update statistics
      set media = case when l_tab(i).tb_statistics.type > 3 then 2 else 1 end
      where unique_key = l_tab(i).unique_key;
    commit;
    exit when c%notfound;
  end loop;
  close c;
end;
/

but probably with a smaller limit than ten million (and therefore more frequent commits, unless you track a separate variable to control that) as you don't want to use too much memory for the collection. You could also reduce the memory used by defining a record type and using that instead of %rowtype, possibly just with the unique key, and changing select * to just the specific columns that match the record type. Or a varray if you only get one column.

(Also not sure if tb_statistics.type is an object type, or more likely the actual table name and a column name, and something was missed modifying the statement for posting. If it is a column in the same table, and this calculation will always be the same as new rows are added, then media could potentially be a virtual column instead.)

It's better to have enough undo space to perform the operation in one transaction, both for efficiency and restartability; but it seems like this is a one-off so perhaps not worth getting that changed, even to a temporary large undo tablespace.

SQL Rownum How to Return Rows Between a Specific Range