How do I select last 5 rows in a table without sorting?

Question

I want to select the last 5 records from a table in SQL Server without arranging the table in ascending or descending order.

Answer 1

Without an order, this is impossible. What defines the "bottom"? The following will select 5 rows according to how they are stored in the database.

SELECT TOP 5 * FROM [TableName]

Answer 2

You can retrieve them from memory.
So first you get the rows in a DataSet, and then get the last 5 out of the DataSet.

Answer 3

This is just about the most bizarre query I've ever written, but I'm pretty sure it gets the "last 5" rows from a table without ordering:

select * 
from issues
where issueid not in (
    select top (
        (select count(*) from issues) - 5
    ) issueid
    from issues
)

Note that this makes use of SQL Server 2005's ability to pass a value into the "top" clause - it doesn't work on SQL Server 2000.

Answer 4

Well, the "last five rows" are actually the last five rows depending on your clustered index. Your clustered index, by definition, is the way that he rows are ordered. So you really can't get the "last five rows" without some order. You can, however, get the last five rows as it pertains to the clustered index.

SELECT TOP 5 * FROM MyTable
ORDER BY MyCLusteredIndexColumn1, MyCLusteredIndexColumnq, ..., MyCLusteredIndexColumnN DESC

Answer 5

There is a handy trick that works in some databases for ordering in database order,

SELECT * FROM TableName ORDER BY true

Apparently, this can work in conjunction with any of the other suggestions posted here to leave the results in "order they came out of the database" order, which in some databases, is the order they were last modified in.

Answer 6

The way your question is phrased makes it sound like you think you have to physically resort the data in the table in order to get it back in the order you want. If so, this is not the case, the ORDER BY clause exists for this purpose. The physical order in which the records are stored remains unchanged when using ORDER BY. The records are sorted in memory (or in temporary disk space) before they are returned.

Note that the order that records get returned is not guaranteed without using an ORDER BY clause. So, while any of the the suggestions here may work, there is no reason to think they will continue to work, nor can you prove that they work in all cases with your current database. This is by design - I am assuming it is to give the database engine the freedom do as it will with the records in order to obtain best performance in the case where there is no explicit order specified.

Assuming you wanted the last 5 records sorted by the field Name in ascending order, you could do something like this, which should work in either SQL 2000 or 2005:

select Name 
from (
    select top 5 Name 
    from MyTable 
    order by Name desc
) a 
order by Name asc

Answer 7

If you know how many rows there will be in total you can use the ROW_NUMBER() function. Here's an examble from MSDN (http://msdn.microsoft.com/en-us/library/ms186734.aspx)

USE AdventureWorks;
GO
WITH OrderedOrders AS
(
    SELECT SalesOrderID, OrderDate,
    ROW_NUMBER() OVER (ORDER BY OrderDate) AS 'RowNumber'
    FROM Sales.SalesOrderHeader 
) 
SELECT * 
FROM OrderedOrders 
WHERE RowNumber BETWEEN 50 AND 60;

Answer 8

Suppose you have an index on id, this will be lightning fast:

SELECT * FROM [MyTable] WHERE [id] > (SELECT MAX([id]) - 5 FROM [MyTable])

Answer 9

select * from table order by empno(primary key) desc fetch first 5 rows only

Answer 10

1. You need to count number of rows inside table ( say we have 12 rows )
2. then subtract 5 rows from them ( we are now in 7 )
3. select * where index_column > 7

select * from users where user_id > ( (select COUNT(*) from users) - 5)

you can order they ASC or DESC

But when using this code

select TOP 5 from users order by user_id DESC

it will not be order easily