How do I write LINQ's .Skip(1000).Take(100) in pure SQL?

Question

What is the SQL equivalent of the .Skip() method in LINQ?

For example: I would like to select rows 1000-1100 from a specific database table.

Is this possible with just SQL? Or do I need to select the entire table, then find the rows in memory? I'd ideally like to avoid this, if possible, since the table can be quite large.

Answer 1

SQL Server 2012 and above have added this syntax:

SELECT *
FROM Sales.SalesOrderHeader 
ORDER BY OrderDate
OFFSET (@Skip) ROWS FETCH NEXT (@Take) ROWS ONLY

Answer 2

In SQL Server 2005 and above you can use ROW_NUMBER function. eg.

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 51 AND 60; --BETWEEN is inclusive

Answer 3

LINQ to SQL does this by using a ROW_NUMBER windowing function:

  SELECT a,b,c FROM 
   (SELECT a,b,c, ROW_NUMBER() OVER (ORDER BY ...) as row_number
    FROM Table) t0
   WHERE to.row_number BETWEEN 1000 and 1100;

This works, but the need to manufacture the row_number from the ORDER BY may result in your query being sorted on the server side and cause performance problems. Even when an index can satisfy the ORDER BY requirement, the query still has to count 1000 rows before startting to return results. All too often developers forget this and just throw a pagination control over a 5 mil rows table and wonder why the first page is returned so much faster than the last one...

None the less, using ROW_NUMBER() is probably the best balance between ease of use and good performance, provided you make sure you avoid the sort (the ORDER BY condition can be satisified by an index).

Answer 4

Try this one:

select * from [Table-Name] order by [Column-Name] 
offset [Skip-Count] rows
FETCH NEXT [Take-Count] rows only

Example:

select * from Personals order by Id
offset 10 rows            --------->Skip 10
FETCH NEXT 15 rows only   --------->Take 15