Trouble using ROW_NUMBER() OVER (PARTITION BY …)

Question

I\'m using SQL Server 2008 R2. I have table called EmployeeHistory with the following structure and sample data:

EmployeeID Date      DepartmentID SupervisorID
1         


        

Answer 1

I would do something like this:

;WITH x 
 AS (SELECT *, 
            Row_number() 
              OVER( 
                partition BY employeeid 
                ORDER BY datestart) rn 
     FROM   employeehistory) 
SELECT * 
FROM   x x1 
   LEFT OUTER JOIN x x2 
                ON x1.rn = x2.rn + 1 

Or maybe it would be x2.rn - 1. You'll have to see. In any case, you get the idea. Once you have the table joined on itself, you can filter, group, sort, etc. to get what you need.