Custom Pagination with Dynamic ORDER BY

SQL Server Denali has a new feature allowing pagination using the order by clause. A common solution needed for the front end is to paginate records prior to sending them to the webserver. More frequently now, we are seeing demormalized data sets being stored in the WebServer’s or a middle tiers cache mechanism. Those solutions however are more difficult to maintain, persist and synchronize. Enter the old fashioned database paging solution. This paging solution initially grabs a subset of a table and counts the records. It then stores ordered results based on the parameter passed into the common table expression. Additional parameters are the number of rows the caller wants on each page and the page number the caller is currently retrieving. [cc lang=”sql”] CREATE PROCEDURE dbo.GetEmployees ( @SortColumn VARCHAR(50) = null, @iRows INT = 10, @iPageNum INT = 1 ) AS BEGIN SET NOCOUNT ON DECLARE @RecordCount int DECLARE @iNbrPages int SET @RecordCount = 0 SET @iNbrPages = 0 SELECT emp.EmployeeID, emp.FirstName, emp.LastName, emp.DateHired INTO #Employees FROM HR.Employees emp WHERE emp.IsTerminated = 1 SELECT @iNbrPages = CEILING(COUNT(1)/(@iRows*1.0)), @RecordCount = COUNT(1) FROM #Employees BEGIN ;WITH PagingCTE ( Row_ID, EmployeeID, FirstName, LastName, DateHired ) AS ( SELECT ROW_NUMBER() OVER(ORDER BY CASE WHEN @SortColumn = ‘EmployeeID’ THEN emp.EmployeeID END ASC, CASE WHEN @SortColumn = ‘FirstName’ THEN emp.FirstName END ASC, CASE WHEN @SortColumn = ‘LastName’ THEN emp.LastName END ASC, CASE WHEN @SortColumn = ‘DateHired’ THEN emp.DateHired END ASC ) AS [Row_ID], emp.EmployeeID, emp.FirstName, emp.LastName, emp.DateHired FROM #Employees emp ) SELECT emp.EmployeeID, emp.FirstName, emp.LastName, […]