var query = db.ExecuteQuery<EmployeeInfo>( @"
WITH EmployeeHierarchy (EmployeeID, LastName, FirstName, ReportsTo, HierarchyLevel) AS
( SELECT EmployeeID,LastName, FirstName, ReportsTo, 1 as HierarchyLevel FROM Employees
WHERE ReportsTo IS NULL

UNION ALL

SELECT e.EmployeeID, e.LastName, e.FirstName, e.ReportsTo, eh.HierarchyLevel + 1 AS HierarchyLevel
FROM Employees e INNER JOIN EmployeeHierarchy eh ON e.ReportsTo = eh.EmployeeID)
SELECT * FROM EmployeeHierarchy ORDER BY HierarchyLevel, LastName, FirstName" );
