Comments on: Easy way to page data in Sql Server

By: Hieu

Hieu — Tue, 16 Jun 2009 01:40:34 +0000

If table have large data, “ROW_NUMBER() OVER (ORDER BY colname)” is very slow.

By: Maxi

Maxi — Mon, 23 Feb 2009 07:47:27 +0000

I have been waiting for this feature too!

By: Jayan

Jayan — Fri, 30 Jan 2009 04:25:35 +0000

Roopa,

ROW_NUMBER() column can’t refer in where clause

please try this Script

— Code 1
select * from (
select Enty_inid ‘StoreID’, Enty_vcName ‘StoreName’ ,
ROW_NUMBER() OVER (order by Enty_inSalesRank desc ) as ‘RowNumber’
from tb_entity )a
where RowNumber between 1 and 10

—code 2
WITH actualSet
(
select Enty_inid ‘StoreID’, Enty_vcName ‘StoreName’ ,
ROW_NUMBER() OVER (order by Enty_inSalesRank desc ) as ‘RowNumber’
from tb_entity
)

SELECT * FROM actualSet where RowNumber between 1 and 10

By: Roopa

Roopa — Wed, 28 Feb 2007 10:37:39 +0000

me too, got the Error

Msg 207, Level 16, State 1, Line 5
Invalid column name ‘RowNumber’.

Here is my query
select Enty_inid ‘StoreID’, Enty_vcName ‘StoreName’ , ROW_NUMBER() OVER (order by Enty_inSalesRank desc ) as ‘RowNumber’ from tb_entity and RowNumber between 1 and 10

By: breichelt

breichelt — Tue, 07 Feb 2006 09:03:29 +0000

carter, I agree that LIMIT is very simple and easy to use, but I think that Row_Number could be used for some interesting scenarios, because you can set th Row_Number based on a field, and then order the actual result set by a different column. I can’t think of anything offhand that you would use that for, but the fact that its there leaves open the possibility.

By: Anonymous

Anonymous — Tue, 07 Feb 2006 00:19:45 +0000

Nice feature, but it still seems more complicated than it needs to be. LIMIT works beautifully as is. I guess there is some other crazy use for the resulting Row Number column that I’m not considering?…

By: breichelt

breichelt — Mon, 30 Jan 2006 15:06:55 +0000

Frans, you clearly know more about the feature than I do, thanks for the insight

By: breichelt

breichelt — Mon, 30 Jan 2006 15:06:24 +0000

Damon, I’m not sure what’s causing the problem that you’re having, I would make sure that you are including the ‘AS RowNumber’ in the select statement.

By: Anonymous

Anonymous — Thu, 26 Jan 2006 15:20:20 +0000

You don’t have to specify tht ORDER BY FirstName at the end of the query. It’s important that if you write paging code like this, you formulate your complete ORDER BY clause in the OVER clause for ROW_NUMBER().

Why is this important? Because the ORDER BY in the select will be executed AFTER the row_number() function has been applied. This means that the ROW_NUMBER() column doesn’t have to be 1, 2, 3, 4, 5 etc.

You should therefore use these rules of thumb:
- place the SELECT’s ORDER BY clause in the ROW_NUMBER’s OVER clause
- instead add an ORDER BY clause to the SELECT to sort the ROW_NUMBER column ASC. This is necessary because by default a SELECT isn’t guaranteed to be sequential, it can be that the rows aren’t in the order in which you would expect. This is by definition of SELECT.

So then, use a WITH statement to construct a CTE:
WITH __actualSet
(
SELECT C.*, ROW_NUMBER() OVER (ORDER BY CompanyName ASC) AS RowNumber FROM Customers C
ORDER BY RowNumber ASC
) SELECT * FROM __actualSet WHERE RowNumber BETWEEN 1 AND 10

By: Anonymous

Anonymous — Thu, 26 Jan 2006 15:13:31 +0000

Thanks to Ben Reichelt over at CodeBetter.com blogs for pointing out the new Row_Number() function in…