Note: The code accompanying this article is available for download here.

In XML-INTO And Optional Elements, I showed a reader how he could use XML-INTO to parse an XML document that effectively contained one of two completely different payloads. As I noted in that article, for this type of “does the document contain X” processing, XML-SAX can be a better choice than XML-INTO. That is the task that I’m going to demonstrate in this tip.

In his email, the reader mentioned that his original intent had been to simply identify the type of payload (Report or Event) and

In Formatting Dates with SQL, Take 2, you have shared a great technique. Function overloading is a real boon to SQL programming. Here’s another way to handle the same issue with what I believe is less code and less invasive (meaning you won’t have to recompile programs that use the FMTDATE service program).

Leave your original FMTDATE function alone, but add the following to the SQL source:

create function xxx/fmtdate
(inDate varchar(8), inFromFmt varchar(8), inToFmt varchar(8))
returns varchar(10)
language SQL
specific FMTDATEA
deterministic
returns null on null input

begin
 declare DateNum numeric (8,0);
 declare OutDate varchar(10);
 set DateNum = 

In DB2 for i 7.2 TR4 and IBM i 7.3, IBM has made a special user-defined table function (UDTF) enhancement that should be shouted from the rooftops. This enhancement is referred to as an inline table function.

Consider the simple example of this UDTF named Get_Customer_Orders:

CREATE OR REPLACE FUNCTION Get_Customer_Orders (
@CustomerID INT,
@StartDate  DATE,
@EndDate    DATE)
RETURNS TABLE (
SalesOrderId INT,
CustomerId   INT,
OrderDate    DATE,
ShipDate     DATE,
SUBTOTAL     DEC(19,4))
LANGUAGE SQL
NO EXTERNAL ACTION
DISALLOW PARALLEL
SET OPTION COMMIT=*NONE,USRPRF=*OWNER,DATFMT=*ISO
    RETURN
        SELECT SalesOrderId,CustomerId,
               OrderDate,ShipDate,SubTotal
          FROM SalesOrderHeader
         WHERE CustomerId=@CustomerId
           AND OrderDate BETWEEN @StartDate AND @EndDate;

What does DB2 do when