The goal is to construct a comma separated string, using a loop but the same way $listtostring(var,",") would do (i.e. "a,b,c,d,e,f,g,h" without starting or ending comma).

What is the best way to do it, concerning the readability of the code and its performances?

To do so, there are more than 5 methods, but in this example we will test 4 :

1) using a "if" in the loop

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When I'm asked questions about SQL, I like Intersystems staff at the WRC, generally ask about the Query Plan.  My feeling is that even before you run a query you should examine the results of Show Plan to confirm that the code is going to give me the results in the manner I would expect.  If I expect it to leverage an index and I see that it is not then I go back and look at what I might have done incorrectly and try to re-write the query to get the index behavior I'm looking for.  To that end, there's a poll below to ask you if think moving the Show Plan button as the first button would be

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We've been tasked with developing a file upload module as part of our wider system, storing scanned documents against a patients profile. Our Intersystems manager suggested storing those files in the DB as streams would be the best approach and it sounded like a solid idea, it can be encrypted, complex indexes, optimized for large files and so on. However the stake holder questioned why would we want to do that over storing them in windows folders and that putting it in the DB was nuts.

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1) Does web service access consume license? 

2) In web service program, we used a connection pool to reuse the session id, but it doesn’t work, the license consume increased quickly, it seems connection pool didn’t work, do you have any sample to do it?

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Hi Developers!

Want to raise security discussion today!

Let's discuss how InterSystems security for applications works. In general, the concept is clear: we have Resources (what to protect), Roles which combine a set of privileges and accesses to Resources and Users which can have this or that Role.

But there is also a concept of Application which also could have a Role.

So you either provide a Role for a User or for an Application.

What do you use in production? What is your strategy and why? Pros, cons?

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Discussion
Andre Larsen Barbosa · Nov 10, 2020
Why change?

I have already asked a question about migrating an Oracle database to Caché, and I was promptly answered. Now, I have one more question, however it is more conceptual. In general, any tool defends its benefits, and looking at Caché's, among many, there is a lot of talk about speed. The question is, if I already have a database, and at the moment, its performance is not a problem, I would like to know what else could influence the change of this database? Remembering that it is functional and without any apparent problem.

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Discussion
Evgeny Shvarov · Sep 28, 2020
%Status usage in ObjectScript

Hi developers!

Want to discuss with you the case of %Status.

If you familiar with ObjectScript you know what is it. I'd love to hear the history of the case why it had appeared in ObjectScript but it turned out that almost every system/library classmethods return %Status and there is a whole set of tools to deal with it.

What is does it gives you the responsibility to check the value or %Status of every system method you call.

E.g. if you save the data of the persistent class,  you should never call like this:

do obj.%Save()

you need to call:

set sc=obj.%Save()

if $$$ISERR(sc) do // something or quit.

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Discussion
Evgeny Shvarov · Sep 21, 2020
Unit Testing Naming Convention

Hi Developers!

Recently we discussed the naming convention on packages we deploy and even made some choices.

Here I want to have a conversation on the naming convention for unit tests.

Of course, we wish every good library has unit tests. Here is the documentation and some good articles(one, two, three) regarding it on the Developer Community.

Let's decide on the naming of UnitTests packages?

The suggestion is that unit test classes will all start with the UnitTest package name.

E.g. if your library's class name is:

johndoe.lib.class

The related unit test class will be:

UnitTest.johndoe.lib.class

What about folders?

The suggestion is that unit test classes will live separately from source classes, e.g. in /tests directory.

Here is the example of a repository with unit tests that are named and placed according to the proposal.

What do you think?

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The use of Source Code Control systems in development is important. And there are a few systems known in the world, like GIT, SVN (Subversion), Perforce, Mercurial. Where the most popular nowadays is the git. Using it is very useful in many cases, but mostly it depends on the code as text, which can be compared between commits, branches, or versions of releases and so on. 

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Application licensing enables InterSystems application partners to take advantage of Caché’s licensing capabilities for their own licensing purposes.

Caché manages customer application licenses just as it does Caché/Ensemble and InterSystems application licenses, maintaining usage counts and acquiring and returning user licenses as needed.

Application licenses consumed by a process or a CSP session are automatically released along with the Caché license consumed by the process or session when a process exits, halts or is deleted from the process table, or when a CSP session times out or is deleted.

More in docs.

Do you use this feature? If so, how?

I'm especially interested in license validation and general workflows?

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Hi All,

We have few queries which are simple selects . For simplicity let's say there is a query that joins two tables and gets few columns and both tables have no indexes.

Select Tab1.Field1, Tab2.Field2
From Table1 Tab1
Join Table2 Tab2
On Tab2.FK = Tab1.PK

When we do query plan for this it shows approx 6 million,  however if we make a simple adjustment to the query

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This is a lesson learned, which I would like to share with community.  


Recently I ran into an issue, where I was using %ConstructClone and it kept cloning extra records, which were not needed.  The record for which I was trying to run a clone had many-to-one relationships.  

The solution to this issue was using param -1.  If you run %ConstructClone(-1) it will not clone relationships, but rather just clone single oref as desired in this case.


I hope this information helps someone who is working with similar records.

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Hi Community!

Sometimes I meet a method which accepts 10+ parameters.

And often I need only the 8th parameter  to  pass. And I call the method something like:

do ##class(Some.Feature).Method(,,,,,,,"flag")

And I don't like this method when I call it like this cause, you know, often I just miss the number of commas and raise some other flag I wanted.

How do you avoid this situations? 

If you meet such a code, how do you call it and sure that you didn't miss the number of ","?

What is a good number of parameters in a method and f you need to pass more parameters in a method what do you do?

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Hi Developers!

InterSystems IRIS stores everything in globals and if we use ObjectScript classes to persist data class documents globals it uses in storage. But if you use globals for calculations, temporary storages, for special indexes or for some other purposes - how do you document it?

Possible options which come to my mind:

1. Macro

#define Array ^MyGlobal

usage:

s $$$Array(1)=1

2. Class parameter

Parameter Array ="^MyGlobal";

Usage:

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Hi Community!

There are two general ways to execute arbitrary SQL  in serverside ObjectScript code: EmbeddedSQL and ObjectScript SQL a.k.a. Dynamic SQL.

E.g. if we want to get the value of the property of instance with a certain ID using SQL we can do:

&sql(SELECT Name INTO :name FROM Sample.Person WHERE ID=1)

write name

Same result with %SQL.Statement:

set rs=##class(%SQL.Statement).%ExecDirect(,"SELECT Name as name FROM Sample.Person where ID=1")
  do rs.%Next()
  write rs.name

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Hi guys!

Suppose you developed a tool, framework, library on InterSystems ObjectScript for InterSystems Data Platform, share it via Open Exchange and want people to install it. 

What is the best strategy if it is a library and supposed to be called from different namespaces?

Here are the following thoughts:

1. Tool's developer should be able to use globals to read/store data the tool needs.

2. Tool's consumer should be confident, that the thing he/she installs will not harm the application's data.

3. A tool should be callable from any application's namespace.

4. Tool's installation(in general) should not request manual security changes (e.g. grant the write access to IRISLIB) and %YourClass is not an option.

5. It's easy to uninstall the tool - just delete the namespace/database (maybe delete some web-apps too).

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Hi, Community!

Have a question for general discussion. 

In ObjectScript we have cls for classes and mac code, which both compile into int code. 

Is there any reason when you use mac instead of cls  for non-persistent classes?

For me the benefits for cls are:

1. Inheritance and other OOP features

2. Auto-documented code 

For mac one visible benefit is easier call in terminal:

do method^Utils(p1,p2)

vs

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