Beginning Microsoft SQL Server 2008 ... - S3 Tech Training

AS
BEGIN
(
EmployeeID int NOT NULL,
ManagerID int NULL
)
/* Since we’ll need to call this function recursively - that is once for each
** reporting employee (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
** here is that we need the first record as something of a primer due to the
** recursive nature of the function - this is how we get it. */
INSERT INTO @Reports
SELECT EmployeeID, ManagerID
FROM HumanResources.Employee2
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.Employee2
WHERE ManagerID = @EmployeeID;
/* This next part would probably be better done with a cursor but we haven’t
** gotten to 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);
END
RETURN;
END
GO
SELECT @Employee = MIN(EmployeeID)
FROM HumanResources.Employee2
WHERE EmployeeID > @Employee
AND ManagerID = @EmployeeID;
Chapter 13: User-Defined Functions
I’ve written this one to provide just minimal information about the employee and his or her manager —
I can join back to the Employee2 table, if need be, to fetch additional information. I also took a little bit
of liberty with the requirements on this one and added in the selected manager to the results. This was
done primarily to support the recursion scenario and also to provide something of a base result for our
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