Thank you Eduard, I appreciate your time on this.  

Maybe I'm just dense, but I still don't get it.  I'm not logged into the server at all.  I'm only connecting to the server through a CSP application.  In order to access the CSP application, I have to log into one of the cache user accounts.  It doesn't seem to matter which cache account I use -- even if I log in as _SYSTEM to run the CSP application, the $ZF shell is executing under user vrogers.

Yes, agreed.  The thing that puzzles me is that the shell environment variables pertain to my personal account, even though when the $ZF command is invoked from the csp page, and I'm logged into an unrelated cache account.  How is it getting the USER vrogers?

If I use $ZF(-1,"whoami > output.txt"), the output is "cacheusr"

But when I use $ZF(-1,"printenv > output.txt"), the output includes:

USER=vrogers
HOME=/home/vrogers

Thank you.

Thank you for the suggestion, Vic!  I think perhaps it was added after the version I'm using (?). At least, I don't find $ZF(-100) in my documentation and when I try the command, it fails.  Guess we're past due for an update.

Thank you Eduard for the quick reply!

However, in my testing, I am not using the terminal, or logged into the OS.  I am calling the $ZF function from a method that is being invoked by a web application.  Is cacheusr somehow tied to a unix username? The cache installation was installed as root, I believe (at least that's who owns the cache binaries and directories).

Thank you Dan and Gerd.  After reviewing your suggestions I reset the storage so that the array property would project in the default way, as a separate table.  After some trial and error, I came up with the following query, which seems to do what I need:

select * from PET.ImageStudy as std

left outer join PET.ImageStudy_Injection as inj  on std.ID=inj.ImageStudy

left outer join PET.PETImageFile as img on img.Study=std.ID AND img.InjKey=inj.element_key  

where Injection_RadioTracer->TracerName=?

Many thanks, Dan, I appreciate any advice regarding the schema definition.  I tried to get at this in an earlier post, but I probably didn't ask the right questions.

Thank you Dan.

It does not appear to be using the default storage, as there is not a separate table for ImageStudy_Injection.  The Injection is stored as a column in the ImageStudy table.  I'm not sure why.  I didn't change any defaults. Though perhaps I tried using a list, instead of array, earlier.  If it's easier when stored in a separate table, can I change the storage mechanism?

Appreciate your help.   I will not get back to working on this until next week.

Thank you Herman, I appreciate the help.

When I change the form attribute to onsubmit ='SubmitForm()' then it stays on the current page after the form is processed regardless of whether the SubmitForm function returns 'true' or 'false'.

So far, the only way I've been successful getting it to go to the new page is when I use onsubmit='return SubmitForm()' and then return false at the end of the SubmitForm function. 

I probably have something else wrong that is causing this behavior.

OK, thank you.

If that is an unusual technique, what is the more standard method?

I just tested your suggestion.  When the function returns 'true', the behavior is the same (it does not load the new page).  However, when the function returns 'false', I do get the desired behavior -- it loads the new page.  Does that make sense?

Thank you!

Thank you! 

In some of the CSP pages in my application, there is code in the OnPreHTTP method to process a button-click or form submit, but in other pages, the form processing is done outside of the OnPreHTTP method.

Does it matter whether or not the form processing code is in the OnPreHTTP method?  Are there reasons why the form processing should or should not go in the OnPreHTTP method?

Wow, thank you! I will try this!

OK, thanks!

So then if I store the Injection element_key (in the case of an array), as a property in the ImageFile object which references the injection, I will be able to get to the various Injection properties from the ImageFile instance?

What would I store in the ImageFile in the case of a list?

Thanks for your help!

OK, thanks.

Is there a good reason to define the Injection property as a list, rather than an array, as I had been planning?

In either case, how do I associate a single element of the Injection property with an ImageFile (ie, should I just store the array key as a property in the ImageFile, or is there a better mechanism)?

Thank you!