#ObjectScript

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 <...>".

Caché offers a number of methods for going through a collection and doing something with its elements. The easiest method uses a while-loop and lets you fulfill the task in an imperative manner. The developer needs to take care of the iterator, jumping to the next element and checking if the loop is within the collection.

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

This post is also available on Habrahabr^ru.

The post was inspired by this Habrahabr article: Interval-associative array^ru→en.

Since the original implementation relies on Python slices, the Caché public may find the following article useful: Everything you wanted to know about slices^ru→en.

Note: Please note that the exact functional equivalent of Python slices has never been implemented in Caché, since this functionality has never been required.

And, of course, some theory: Interval tree^ru→en.

All right, let’s cut to the chase and take a look at some examples.

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.

On the back of my recent post on writing bug-less code I wanted to raise a few suggestions (to ISC) that would help prevent certain types of bugs at compile time. I've probably missed a few, but these are the main ones in my mind. Please contribute more suggestions.

Btw, these also serve as potential gotchas for new COS developers.

Inspired by the article "Declarative development in Caché" that's still trending on the dev com. The OP explored a functional style of iterating over a collection. A comment today suggested "Caché would need syntax support for anonymous functions".

With Macros you can kind of get anonymous like syntax using dot notation.

This is not production code, but it does work. First the macros...

So I know it's been a while, and I hate to let my adoring fans down... just not enough to actually start writing again. But the wait is over and I'm back! Now bask in my beautiful ginger words!

For this series, I am going to look at some common problems we see in the WRC and discuss some common solutions. Of course, even if you find a solution here, you are always welcome to call in and expression you gratitude, or just hear my voice!

This week's common problem: "My query returns no data."

I was benchmarking the populate utils when I noticed something strange. Consider this simple benchmarking method:

Recently I wrote about automatic removal of system methods from the codebase.

Today, I'm ready to present you a working solution (codename: SMR) for this task.

Here you have an easy way to write and execute COS code from your unix scripts. This way one does not need to write routines or even open Studio or Atelier. It can be an option for simple and small actions for instance things like installation tasks or compiling.

See sample bash script (compile.sh) to compile classes:

Have you tried $Translate for date conversion?

USER>write $Translate("Dd.Mm.WwYy","WwYy-Mm-Dd","2015-08-02")

02.08.2015

Stolen from Russian forum and Alexander Koblov.

Cache tricks

Several years ago, long before Developer Community Portal was launched, I published a series of Caché tricks at one of Czech web sites. In this article, I’m posting translated version of one of them.

Capturing output of someone else’s methods or routines

Suppose you, or someone else created a useful method or routine, that was producing some computation that you’d like to benefit from, but the routine was writing output to process principal device.

You would like to use the data, but you need it not written to a device, but assigned to a variable. And, for any reason, you can’t modify the code. What can you do?

Order is a necessity for everyone, but not everyone understands it in the same way
(Fausto Cercignani)

Disclaimer: This article uses Russian language and Cyrillic alphabet as examples, but is relevant for anyone who uses Caché in a non-English locale.
Please note that this article refers mostly to NLS collations, which are different than SQL collations. SQL collations (such as SQLUPPER, SQLSTRING, EXACT which means no collation, TRUNCATE, etc.) are actual functions that are explicitly applied to some values, and whose results are sometimes explicitly stored in the global subscripts. When stored in subscripts, these values would naturally follow the NLS collation in effect (“SQL and NLS Collations”).