Question

Many applications have grids that display data from a database table one page at a time. Many of them also let the user pick the number of records per page, sort by any column, and navigate back and forth through the results.

What’s a good algorithm to implement this pattern without bringing the entire table to the client and then filtering the data on the client. How do you bring just the records you want to display to the user?

Does LINQ simplify the solution?

Answer 1

On MS SQL Server 2005 and above, ROW_NUMBER() seems to work:

T-SQL: Paging with ROW_NUMBER()

DECLARE @PageNum AS INT; DECLARE @PageSize AS INT; SET @PageNum = 2; SET @PageSize = 10;  WITH OrdersRN AS (     SELECT ROW_NUMBER() OVER(ORDER BY OrderDate, OrderID) AS RowNum           ,OrderID           ,OrderDate           ,CustomerID           ,EmployeeID       FROM dbo.Orders )  SELECT *    FROM OrdersRN  WHERE RowNum BETWEEN (@PageNum - 1) * @PageSize + 1                    AND @PageNum * @PageSize  ORDER BY OrderDate          ,OrderID;