If you have system tables implementing the "VERSIONPROPERTY" functionality, you may encounter error 5800. This article explains how this error occurs and provides solutions to resolve the issue.

When version checking is implemented, the property specified by VERSIONPROPERTY is automatically incremented each time an instance of the class is updated (either by objects or SQL).

For example:

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Here are a few examples of conversions and operations you might need, along with links to documentation where you can learn more.

At the time I wrote this, Eastern Daylight Time was in effect for my Caché system.

How Caché keeps the time and date

Caché has a simple time format, with a longer range of recognized dates compared to some other technologies.

The current time is maintained in a special variable $HOROLOG ($H):

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Article
· Sep 11, 2024 9m read
Dates with InterSystems

Do not let the title of this article confuse you; we are not planning to take the InterSystems staff out to a fine Italian restaurant. Instead, this article will cover the principles of working with date and time data types in IRIS. When we use these data types, we should be aware of three different conversion issues:

  1. Converting between internal and ODBC formats.
  2. Converting between local time, UTC, and Posix time.
  3. Converting to and from various date display formats.

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Article
· May 20, 2017 10m read
Localization in Caché DBMS

This is a translation of the following article. Thanks @Evgeny Shvarov for the help in translation.

Let's assume that you wrote a program that shows "Hello World!", for example:

  write "Hello, World!"

The program works and everyone is happy.

With time, however, your program becomes more complex, gets more features and you eventually need to show the same string in different languages. Moreover you don't know the number and names of these languages.

The spoiler below contains a description of how the task of multi-language localization is solved in Caché.

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Article
· Mar 4, 2022 4m read
How to become a time lord - Time travel

Time travel is like visiting Paris. You can't just read the guide, you have to throw yourself into it. Eat the food, use the wrong verbs, get double the charges, and end up kissing complete strangers.

The Doctor

We are now going to travel through time, that is, we are going to see future and past dates and how to calculate them in different formats. The TARDIS doesn't wait, take the controls and hold on tight.

Travel in TARDIS

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Article
· Jul 26, 2019 3m read
Dynamic SQL to Dynamic Object

Hello community! I have to work with queries using all kinds of methods like embedded sql and class queries. But my favorite is dynamic sql, simply because of how easy it is to manipulate them at runtime. The downside to writing a lot of these is the maintenance of the code and interacting with the output in a meaningful way.

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Article
· Jul 7, 2017 19m read
Indexing of non-atomic attributes

Quotes (1NF/2NF/3NF)ru:

Every row-and-column intersection contains exactly one value from the applicable domain (and nothing else).
The same value can be atomic or non-atomic depending on the purpose of this value. For example, “4286” can be
  • atomic, if its denotes “a credit card’s PIN code” (if it’s broken down or reshuffled, it is of no use any longer)
  • non-atomic, if it’s just a “sequence of numbers” (the value still makes sense if broken down into several parts or reshuffled)

This article explores the standard methods of increasing the performance of SQL queries involving the following types of fields: string, date, simple list (in the $LB format), "list of <...>" and "array of <...>".

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InterSystems FAQ rubric

In the sample below, an image file is encoded into a Base64 string in a class property, saved, decoded again with Base64, and restored to another file.

【Usage class】

Class User.test Extends %Persistent
{
Property pics As %GlobalBinaryStream;
}


【When importing】

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The DeclarativeCOS project is a heartfelt cry about programming in the COS language.

The purpose of the project is to draw attention of the public to improving the inner core of COS.

The idea of the project is the support of a laconic syntax for cycles and collections.

So what is this laconic something that I have come up with? Welcome to the examples below!

Examples

The key concept underlying the project is the declarative approach to writing code. You need to specify WHAT should be used and HOW.

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This article was written as an attempt to share the experience of installing the InterSystems Caché DBMS for production environment.
We all know that the development configuration of a DBMS is very different from real-life conditions.
As a rule, development is carried out in “hothouse conditions” with a bare minimum of security measures, but when we publish our project online, we must ensure its reliable and uninterrupted operation in a very aggressive environment.

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Hi Developers!

Sometimes we need to import CSV data programmatically to InterSystems IRIS either from CSV or from URL. And we expect the class with proper datatypes to be created and the data to be imported.

I published a module csvgen on Open Exchange which does exactly that.

If you just need the CSV file be imported into IRIS you can do the following:

USER>do ##class(community.csvgen).Generate("/usr/data/titanic.csv",,"Data.Titanic")

Class name: Data.Titanic
Header: PassengerId INTEGER,Survived INTEGER,Pclass INTEGER,Name VARCHAR(250),Sex VARCHAR(250),Age INTEGER,SibSp INTEGER,Parch INTEGER,Ticket VARCHAR(250),Fare MONEY,Cabin VARCHAR(250),Embarked VARCHAR(250)
Records imported: 891
USER>

Or if you have the CSV on the internet, e.g. COVID-19 Data on Github you can get the data in the following way:

USER>d ##class(community.csvgen).GenerateFromURL("https://raw.githubusercontent.com/CSSEGISandData/COVID-19/master/csse_covid_19_data/csse_covid_19_daily_reports/05-29-2020.csv",",","Data.Covid19")

Class name: Data.Covid19
Header: FIPS INTEGER,Admin2 VARCHAR(250),Province_State VARCHAR(250),Country_Region VARCHAR(250),Last_Update DATE,Lat MONEY,Long_ DOUBLE,Confirmed INTEGER,Deaths INTEGER,Recovered INTEGER,Active INTEGER,Combined_Key VARCHAR(250),Incidence_Rate DOUBLE,Case-Fatality_Ratio DOUBLE
Records imported: 3522
USER>

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Methods written in ObjectScript can use pass-by-reference arguments to return information to the caller. Python doesn’t support pass-by-reference arguments, so Embedded Python in IRIS doesn’t support them either. That's it, that's the end of the post, hope you liked it. 😉 But wait, what about the Classic Rock & Roll?

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For some years I missed being able to offer, to everybody interested in ObjectScript, a tutorial more or less complete, to start with ObjectScript. Something that could help more and make things easier to those new developers that come to our technology... something intermediate, halfway between the common "Hello World!", that doesn't really get you further, and the "Advanced Training", that is unaffordable because of lack of time,etc.

If there were something truly helpful not only as an introduction to the ecosystem, but as a starting point, as a boost, to really start to walk into ObjectScript and move forward by yourself... wouldn't that be awesome?

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Hi Developers!

Suppose you have a persistent class with data and you want to have a simple Angular UI for it to view the data and make CRUD operations.

Recently @Alberto Fuentes described how to build Angular UI for your InterSystems IRIS application using RESTForms2.

In this article, I want to tell you how you can get a simple Angular UI to CRUD and view your InterSystems IRIS class data automatically in less than 5 minutes.

Let's go!

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Advent of Code is a series of 25 small programming challenges, it's an ideal way for beginners to start learning a computer language, and for advanced people to sharpen their programming skills.

There are small and bigger puzzles, which you can solve typically in half an hour to a few hours. (Looking at the leaderboard, the top aces can do them in less than 10 minutes.)

Advent of Code is created by Eric Wastl, you can find all info on https://adventofcode.com/.

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Article
· Dec 23, 2015 1m read
Caché ObjectScript Quick Reference

In the Caché Foundations course, students are learning about Caché Development and ObjectScript syntax at the same time. To help students complete the exercises, we provide an ObjectScript Quick Reference (aka "the Cheat Sheet").

It is not a reference for all of ObjectScript! It is a list of the ObjectScript commands and functions that students use during the course, along with common syntax for objects, collections, etc. It also contains some useful macros.

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