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manojagrawal · Beginner Joined: 25 Feb 2003 Posts: 124 Topics: 29

Hi,

Quite a few posts coming up on IMS from me. Well can anyone tell me a good book on IMS Programming using PL/I???

Now, can we have 2 pointers pointing to the same IMS DB. What I want is a pointer which would read rows with a certain condition and another pointer which would read rows with an additional condition to the first, so that it is a subset.

How do we do this?

Regards
Manoj.

manojagrawal · Beginner Joined: 25 Feb 2003 Posts: 124 Topics: 29

Hi,

Well this is what I want to do. And this is the reason why I thought 2 pointers would work. Would anyone have a suggestion as to any way to solve this?

The IMS DB i have contains records like this:

Now what I want to do is this. I want to fill the third column of each Master Record using the Pre-dominant value of the Sub Records.

What i was thinking is to use 2 pointers. One which would read all master records and another which would read each sub record for a master record. Then I would see the varoius values of the 3rd col in the sub records and store a count of them in an array alongwith the value of the third col. When reading of all sub records of a Master record is done, i would take the max count from the array and the corresponding value would be filled in the master record. Then I would move to the Next Master record. Something Like using Cursors.

So does any body have an idea on this. Suggestions Please. Would be greatly appreciated.

Regards,
Manoj.

Bithead · Posted: Wed Mar 26, 2003 12:12 pm Post subject:

By pointers, I assume you mean PSBs. I have never used PL/I.

You will need 2 PCBs. The SSA for the first PCB will have the parent segment name only and will set parantage using a command code of D. Issue a GN on this PCB until you get to the end of the database.

Issue a GNP against the second PCB, restricting to the appropriate child segment, until all the sgements are processed.

Update the parent thru PCB 1.

Try looking at the IMS manuals. They tend to have examples in assembler and PL/I.

manojagrawal · Beginner Joined: 25 Feb 2003 Posts: 124 Topics: 29

Hi Bithead,

Whats happening is all these records are part of one SEGMENT.

In that case, i am confused as to how we can do a parent child relationship. Can you please explain in more detail.

Also which would be the right Manual to use. I have looked thru and there are so many. Gets me confused. You have any particular one's to suggest?

Regards,
Manoj.

Bithead · Posted: Fri Mar 28, 2003 9:05 am Post subject:

Issue the GHU or GHN on the parent and set parentage. Issue the GNP against the child segment and process each occurrance on that segment. If there are more child segments for this parent, process them then update the parent.

manojagrawal · Beginner Joined: 25 Feb 2003 Posts: 124 Topics: 29

Hi Bithead,

As I mentioned these are all part of one segment and do not have a parent child relationship.

However, by using 2 PCB's and with simple GU calls against the segment i did manage to get the 2 pointers that i required.

Thanks for your suggestions!!!!

Regards,
Manoj.