How to select the nth row in a SQL database table?

Question

I\'m interested in learning some (ideally) database agnostic ways of selecting the nth row from a database table. It would also be interesting to see how this can b

Answer 1

For SQL server, the following will return the first row from giving table.

declare @rowNumber int = 1;
    select TOP(@rowNumber) * from [dbo].[someTable];
EXCEPT
    select TOP(@rowNumber - 1) * from [dbo].[someTable];

You can loop through the values with something like this:

WHILE @constVar > 0
BEGIN
    declare @rowNumber int = @consVar;
       select TOP(@rowNumber) * from [dbo].[someTable];
    EXCEPT
       select TOP(@rowNumber - 1) * from [dbo].[someTable];  

       SET @constVar = @constVar - 1;    
END;

Answer 2

T-SQL - Selecting N'th RecordNumber from a Table

select * from
 (select row_number() over (order by Rand() desc) as Rno,* from TableName) T where T.Rno = RecordNumber

Where  RecordNumber --> Record Number to Select
       TableName --> To be Replaced with your Table Name

For e.g. to select 5 th record from a table Employee, your query should be

select * from
 (select row_number() over (order by Rand() desc) as Rno,* from Employee) T where T.Rno = 5

Answer 3

There are ways of doing this in optional parts of the standard, but a lot of databases support their own way of doing it.

A really good site that talks about this and other things is http://troels.arvin.dk/db/rdbms/#select-limit.

Basically, PostgreSQL and MySQL supports the non-standard:

SELECT...
LIMIT y OFFSET x 

Oracle, DB2 and MSSQL supports the standard windowing functions:

SELECT * FROM (
  SELECT
    ROW_NUMBER() OVER (ORDER BY key ASC) AS rownumber,
    columns
  FROM tablename
) AS foo
WHERE rownumber <= n

(which I just copied from the site linked above since I never use those DBs)

Update: As of PostgreSQL 8.4 the standard windowing functions are supported, so expect the second example to work for PostgreSQL as well.

Update: SQLite added window functions support in version 3.25.0 on 2018-09-15 so both forms also work in SQLite.

Answer 4

I suspect this is wildly inefficient but is quite a simple approach, which worked on a small dataset that I tried it on.

select top 1 field
from table
where field in (select top 5 field from table order by field asc)
order by field desc

This would get the 5th item, change the second top number to get a different nth item

SQL server only (I think) but should work on older versions that do not support ROW_NUMBER().

Answer 5

SQL SERVER

---

Select n' th record from top

SELECT * FROM (
SELECT 
ID, NAME, ROW_NUMBER() OVER(ORDER BY ID) AS ROW
FROM TABLE 
) AS TMP 
WHERE ROW = n

select n' th record from bottom

SELECT * FROM (
SELECT 
ID, NAME, ROW_NUMBER() OVER(ORDER BY ID DESC) AS ROW
FROM TABLE 
) AS TMP 
WHERE ROW = n

Answer 6

Contrary to what some of the answers claim, the SQL standard is not silent regarding this subject.

Since SQL:2003, you have been able to use "window functions" to skip rows and limit result sets.

And in SQL:2008, a slightly simpler approach had been added, using
OFFSET skip ROWS FETCH FIRST n ROWS ONLY

Personally, I don't think that SQL:2008's addition was really needed, so if I were ISO, I would have kept it out of an already rather large standard.