Processing simple XML using XML-INTO

I had received notification from a supplier that they were changing the order file they send my employer. Previously they sent a Microsoft Excel spreadsheet, starting the end of this month it would now be a XML file. In the past if I need to convert a XML into data in an IBM i file I would use the EDI application to do the conversion. As the XML is so simple I decided to process its contents in my own RPG program.

The operation code XML-INTO takes information from elements in the XML document and, in my example, places them into data structure subfields. I believe that this operation code has been around since V5R4, I am just a late comer to using it.

The XML document I will be using in these (very) simple examples contains a (very short) list of names and the city and state the person is in. The proposed format of the XML file the supplier sending me is very simple too, no need for anything complicated.

Handling divided by zero in SQL

One of the messages that annoys me the most is "Attempt to divide by zero". I am sure every programmer, no matter, what language they use, has encountered this at least once. It frustrates me is there is not much we can do to fix the error once it has happened. It annoys me that this can be handled very well within the program to prevent the error.

Before I get started I know there are a couple of different ways the division calculation can be described, I did check. I will be using the following:

Result = Dividend / Divisor

It is the Divisor that must be zero for this error to occur, as:

Creating a list of journaled files, improved

In my previous post about making a list of files in a library that are journaled I stated that I could not find this information in any Db2 for i view or table function.

Krister Karlsson brought to my attention that the information is available in the OBJECT_STATISTICS table function. Looking at the documentation from IBM it would appear to have been added in the previous round of Technology Refreshes.

Rather than using the Display Object Description command, DSPOBJD, I can get the information I desire from a simple Select statement.

New Technical Refreshes released today

The latest IBM i Technical Refreshes for version 7.2 and 7.3, that were announced in February, were released earlier today.

The information about the PTFs can be found here:

• IBM i 7.3 TR4: SF99727
• IBM i 7.2 TR8: SF99717

One thing to be aware of is that these probably do not contain the PTFs for the latest changes to RPG, these will be released on Monday March 19. These PTFs are listed here.

Creating a list of journaled files

"How do we know what files are journaled in library x?" one of the programmers asked me. A straight forward question, but where to find the information?

I could not find reference to journals in either the Db2 for i Views SYSTABLES or SYSTABLESTAT.

I could find a fields for journal information using the Display File Description command, DSPFD, but only in the types of information that I can display or print, not in those that create an outfile.

I might have used an API, QUSLOBJ with format type OBJD0500 or QUSROBJD format OBJD0400, if I only wanted to know about one file, but I want a "list" of files.

Creating your own commands, part 2

In the last post, Creating your own commands, part 1, I wrote about a lot of the basics in creating your own IBM i commands. In this post I am going to show how to write a validation program for the command, how to add help, and return a value from a command.

I am going to create a validation program for the command with the file and library I showed in the previous post.

File & library (TESTCMD) Type choices, press Enter. File . . . . . . . . . . . . . . Name Library . . . . . . . . . . . *LIBL Name, *LIBL

My validation program will check if the file entered exists. Like the program the command calls the validation program is passed one parameter for each parameter the command has. This command will pass a parameter, 20 characters long, that contains the file and library name.

Creating your own commands, part 1

We have been able to create our own commands, I believe, since the AS400 was first launched. Why would I want to create my own commands?

I create them just for ease of use. In my opinion it is easier to remember:

ITTOOLS/ITTOOLS

Than this:

CALL ITTOOLS/ITT001

Having the source for suggested indexes created for you

Last year I wrote about using the Db2 for i index advisor to suggest indexes that would improve the performance of your SQL statements. I showed how you could copy data from its results to use to create for SQL statements to create the suggested Indexes. Recently I found a Db2 for i Procedure that makes this so much easier as it will create source members for the suggested Indexes.

I can use the Index Advisor View to see what Indexes are suggested for the FILE1 in the library MYLIB.

01 SELECT SYS_DNAME AS LIBRARY, 02 SYS_TNAME AS TABLE, 03 FIRSTADV AS FIRST_ADVISED, 04 TIMESADV AS NBR_TIMES, 05 KEYSADV AS ADVISED_KEYS 06 FROM QSYS2.SYSIXADV 07 WHERE SYS_DNAME = 'MYLIB' 08 AND SYS_TNAME = 'FILE1'

Making IP connections easier between IBM i partitions

I have mentioned in previous posts regarding using DDM files and configuring remote database connections that there is a difference in using SNA and IP for the connection protocol.

When you use SNA to connect everything performed on the remote IBM i is performed as the user profile QUSER. It is impossible to discriminate between valid requests for the files/tables and others trying to get at data they should not be authorized to.

CRTDDMF FILE(QTEMP/DDMFILE1) RMTFILE(OTHERLIB/RMTFILE) RMTLOCNAME(SYSTEM2)

IBM i 7.3 TR4 and 7.2 TR8 announced

I find it interesting that the announcements of new Technical Refreshes are always made on a Tuesday. After finding empty pages for the new TRs last week it was obvious that the announcement would happen soon. What does the latest announcement contain:

The biggest announcement are the new Power9 chips are coming.

Configuring database connection between two IBM i

In my day job I work in an environment where there are multiple PowerSystems servers, and many of them have multiple IBM i partitions. I was tasked to gather information from most of the partitions into one location. I decided to use SQL to fetch the information from the various sources.

I used the following two methods to connect to the other partitions using the partition name:

CONNECT TO SYSTEM2   or   SELECT * FROM SYSTEM2.OTHERLIB.RMTFILE

When debugging my program I found that when I tried to connect to some of the partitions I received a SQLCOD value of -950 and the following message:

New Technology Refreshes are coming

In the past the twice yearly Technology Refreshes updates for the current releases of IBM i were announced in the middle of February and the beginning of October, to coincide with Common USA events.

While Common does not appear to have a Spring conference this year (at the time I am writing this post their website is unavailable), the announcement of IBM i 7.3 TR4 and 7.2 TR8 could still be on track for this month as I have found empty pages for them in IBM developerWork's website.