sql server 2005 UDF 执行有关问题

USE AdventureWorksgoCREATE FUNCTION dbo.fnGetReports       (@EmployeeID AS int)        RETURNS @Reports TABLE       (        EmployeeID int not NULL,        ManagerID int not NULL        )ASBEGIN/*Snce we'll need to this function recursively - that is once for each reporting ** emloyee (to make sure that they don't have reports of their own),    we need a holding  ** variable to keep track of which employee we're currently working on.*/ DECLARE @Employee AS int/*This inserts the current employee into our working table.The significance hereis**that we need the first record as something of s primer due to the recursive nature  of the function - this is how we get it.*/INSERT INTO @Reports   SELECT EmployeeID,ManagerID   FROM HumanResources.Employee   WHERE EmployeeID = @EmployeeID/*Now we also need a primer for the recursive calls we're getting ready to start   making to this function .This would probably be better done with a cursor ,but we  haven't gotten to that chapter yet,so...*/SELECT @Employee = MIN(EmployeeID)FROM HumanResources.EmployeeWHERE ManagerID = @EmployeeID/* This next part would probably be better done with a curson but we haven't gottento that chapter yet ,so we'll fake it .Notice the recursive call to our function!*/WHILE @Employee IS NOT NULL   BEGIN      INSERT INTO @Reports           SELECT *           FROM fnGetReports(@Employee)                      SELECT @EmployeeID = MIN(EmployeeID)           FROM HumanResources.Employee           WHERE EmployeeID > @Employee                 AND ManagerID = @EmployeeID   END RETURN ENDGO  

SELECT * FROM fnGetReports(12)