Parms built in function added to CL

With every new release I go through all the "What's new for this release" section of IBM's KnowledgeCenter. For IBM i 7.4 and the CL programming language there is only one addition this release: %PARMS built in function. It appears to be identical to the %PARMS built in function in RPG. It is the way to determine how many parameters have been passed to a program or procedure, and from that stop the program from erroring if too few parameters are passed.

In the past I wrote about coping with to few parameters being passed to a CL program, but the new BiF is a lot neater and easier for someone else to understand.

As I said above %PARMS is available in RPG:

Executing CL commands using RUNSQLSTM

The Run SQL Statements command, RUNSQLSTM, runs all of the SQL statements that are in a particular source member. I use the command a lot as I put all of my SQL statements to create Tables, Views, Indexes, and the statements to Alter them into source members, and I update the member whenever I make a change to the object. I also put miscellaneous groups of SQL statements into source members, that I can then execute whenever I want.

I use RUNSQLSTM so much I have a PDM option defined so I don't have to type in the command and all the parameters I care about.

Opt Command RS RUNSQLSTM SRCFILE(&L/&F) SRCMBR(&N) COMMIT(*NONE) ERRLVL(20)

In the past if I ever wanted to run a CL command in one of these member I would use SQL's QCMDEXC procedure.

More about SQL Sequences

Last week I wrote a post introducing what SQL Sequences are. Having had a chance to "play" with them some more I wanted to write about what I have discovered.

Before I go into any examples I need to have some Sequences to "play" with:

CREATE SEQUENCE MYLIB.BY_ONE START WITH 1 INCREMENT BY 1 NO MAXVALUE NO CYCLE ; CREATE SEQUENCE MYLIB.BY_TEN START WITH 10 INCREMENT BY 10 NO MAXVALUE NO CYCLE ; CREATE SEQUENCE MYLIB.BY_100 START WITH 100 INCREMENT BY 100 NO MAXVALUE NO CYCLE ; CREATE SEQUENCE MYLIB.BY_THREE START WITH 30 INCREMENT BY 3 NO MAXVALUE NO CYCLE ;

Using a SQL Sequence to renumber a column

The title sounds a bit strange, but so is the subject of this post. There is a thing in Db2 for i that I can create called a Sequence. A Sequence uses the rules I give it to return to me a sequential value I can use to update column in a table.

I am sure it will become a bit clearer when I give my example.

I have ten students who have completed taken a course. At the end of the course the students take a test. The results of this test are contained in a SQL table I created, along with their name.

Extracting the job's name from the Job Name

Update

If you are using IBM i 7.5, or greater, you ought considering using JOB_NAME, JOB_NUMBER, JOB_USER scalar functions or the JOB_NAME_DETAILS table function instead.

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I was asked was there an easy way to extract the name from the Job Name column in the Db2 for i table function ACTIVE_JOB_INFO.

The IBM i Job Name consists of three parts:

1. Number
2. User profile
3. Name given to the job when it was started

For example:

741232/SIMONH/QPADEV0001

The issue when extracting the name from the Job Name is it does not always start in the same position. The number is always six long, but the user profile can be any length from one to ten. This means that the name could start anywhere from the tenth to the nineteenth position in the Job Name.

Using SQL to determine if subsystem is started

The question came in two parts:

1. Is it possible to know whether a subsystem has been started?
2. If it is started how can I determine the number of jobs running in it?

To answer these questions I decided to use a Db2 for i table function I have written about before ACTIVE_JOB_INFO.

One of the parameters that can be used with ACTIVE_JOB_INFO is one that narrows the results to just all active subsystems. If I wanted to know if QINTER subsystem was active I could use the following SQL statement in my favorite SQL client:

Easiest way to retrieve the program's name in a CL program

It has always been a bit of a pain to get the name of the CL current program using the Receive Message command, RCVMSG. Therefore, I was excited when I received an example program showing a much simpler way of getting the same information by using a Machine Interface program.

The program I am going to show needs to be created as a CLLE member, and compiled using the Create Bound CL program , CRTBNDCL. As the call procedure command, CALLPRC, is not permitted in CLP source members.

My CLLE program will be calling the MI program _MATPGMNM, it is important to notice that the program name starts with an underscore ( _ ). I cannot use a CALL command, I must use the CALLPRC command instead.

My first example is the simplest program I could write to call this MI program, and have the current program name and library returned.

Which users are authorized to these files and tables?

This post started as one idea, and the more I played it morphed into something else.

The starting point was the SYSTABAUTH view. This view displays the authority of all DDS PF and LF files, SQL DDL tables, views and indexes, in all libraries, except QTEMP. It contains the same information that is shown when I use the Display Object Authority command, DSPOBJAUT. As it is a view I can retrieve the results from SQL statements and manipulate it any way I desire.

In these examples I will be using a few of the view's columns:

1. GRANTEE:  the user profile that has been authorized to the object
2. SYSTEM_TABLE_SCHEMA:  the system name of the library that contains the object
3. SYSTEM_TABLE_NAME:  the system name of the object
4. PRIVILEGE_TYPE:  the various authorities granted to the user profile to this object

There are seven different types of privilege that can be given to an object:

Checking for Firmware updates

You might want to share this post with the System Admin of the IBM i you use, as this will probably more of more interest to him or her than to a developer type of person.

Wikipedia defines firmware as:

Firmware is a specific class of computer software that provides the low-level control for the device's specific hardware.

Wikipedia: Firmware

Despite the term "Firmware Currency" being widely used by many different hardware platforms I have been unable to find a definition. From what I can ascertain "firmware currency" appears to be the equivalent of firmware release.

With the latest Technology Refresh for IBM i, TR6, a new view has been added to allow us to compared the firmware fix level installed on the IBM i partition to the recommended fix level from the remote Fix Level Recommendation Tool, FLRT. To be able to use this view the IBM i partition being used must be able to access the internet and be able to reach the FLRT website:
https://www14.software.ibm.com/support/customercare/flrt/liteTable?prodKey=fw&format=json

It is now easier searching message files

I have always found it a bother to search for IBM i message ids. Which message file contains the particular message id I want? What messages could I use for a date validation error? Etc. I always had wished for an easier way to perform searches like this.

Fortunately the latest Technology Refresh, IBM i 7.3 TR6, has a new Db2 for i view to make my searches for messages so much easier. The view MESSAGE_FILE_DATA returns a row for each message from all the message files in the IBM i partition I am using. I am not going to describe what the columns are here, as I think their names explain what they contain. For a full list of all the columns contained in this view click on the link to IBM's documentation at the bottom of this post.

Everything you can see with the Display Message Description command, DSPMSGD, is in this view. Using this view I do not have to give the message file's name when searching for a particular message id. For example if I am looking for the description for the message "RSC0082" I would have used the DSPMSGD command:

Thursday's video now online

The video recording of the presentation I made with New Generation Software, Inc. is now online, you can watch it by clicking here.

New release, IBM i 7.4, day

The new release of IBM i is out today!

If your Power server has a POWER8 or POWER9 chip, then you are one of the fortunate ones who can install the new release.

You can read the announcement document for IBM i 7.4 here.

Most of the new programming features I have been writing about in IBM i 7.3 TR6 are in 7.4 too.

The biggest thing to happen to Db2 for i for years, Db2 Mirror for i, is only available for this new release. If you are one of those moving to 7.4 and you start using Db2 Mirror for i I am interest to hear your thoughts about it.

For more information on what is available in the new release, and 7.3 TR6, visit these links:

• My initial findings on the day of the announcement
• My pick for the biggest things in IBM i 7.4